Telit LE910Cx Hardware Design Guide r22
Telit LE910Cx Hardware Design Guide r22
Telit LE910Cx Hardware Design Guide r22
HW User Guide
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Rev. 22 – 2020-04-02
LE910Cx HW User Guide
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NOTICE
While reasonable efforts have been made to assure the accuracy of this document, Telit
assumes no liability resulting from any inaccuracies or omissions in this document, or from
use of the information obtained herein. The information in this document has been
carefully checked and is believed to be reliable. However, no responsibility is assumed for
inaccuracies or omissions. Telit reserves the right to make changes to any products
described herein and reserves the right to revise this document and to make changes
from time to time in content hereof with no obligation to notify any person of revisions or
changes. Telit does not assume any liability arising out of the application or use of any
product, software, or circuit described herein; neither does it convey license under its
patent rights or the rights of others.
It is possible that this publication may contain references to, or information about Telit
products (machines and programs), programming, or services that are not announced in
your country. Such references or information must not be construed to mean that Telit
intends to announce such Telit products, programming, or services in your country.
COPYRIGHTS
This instruction manual and the Telit products described in this instruction manual may be,
include or describe copyrighted Telit material, such as computer programs stored in
semiconductor memories or other media. Laws in the Italy and other countries preserve
for Telit and its licensors certain exclusive rights for copyrighted material, including the
exclusive right to copy, reproduce in any form, distribute and make derivative works of the
copyrighted material. Accordingly, any copyrighted material of Telit and its licensors
contained herein or in the Telit products described in this instruction manual may not be
copied, reproduced, distributed, merged or modified in any manner without the express
written permission of Telit. Furthermore, the purchase of Telit products shall not be
deemed to grant either directly or by implication, estoppel, or otherwise, any license under
the copyrights, patents or patent applications of Telit, as arises by operation of law in the
sale of a product.
IV. Trademarks
TELIT and the Stylized T Logo are registered in Trademark Office. All other product or
service names are the property of their respective owners.
APPLICABILITY TABLE
This documentation applies to the following products:
CONTENTS
1. INTRODUCTION ...............................................................................................9
Scope ................................................................................................................9
Audience ...........................................................................................................9
Contact Information, Support ............................................................................9
Text Conventions ............................................................................................10
Related Documents .........................................................................................11
4. ELECTRICAL SPECIFICATIONS...................................................................37
Absolute Maximum Ratings – Not Operational................................................37
Recommended Operating Conditions .............................................................37
Logic Level Specifications ...............................................................................38
4.3.1. 1.8V Pads - Absolute Maximum Ratings .........................................................38
4.3.2. 1.8V Standard GPIOs ......................................................................................38
4.3.3. 1.8V SD Card Pads .........................................................................................39
5. HARDWARE COMMANDS.............................................................................42
Turning on the LE910Cx Module .....................................................................42
Initialization and Activation State .....................................................................42
Turning off the LE910Cx Module .....................................................................45
5.3.1. Shutdown by Software Command ...................................................................46
5.3.2. Hardware Shutdown ........................................................................................47
5.3.3. Unconditional Hardware Shutdown .................................................................48
Powering OFF the Module ..............................................................................49
Fast Power Down ............................................................................................50
5.5.1. Fast Shut Down by Hardware..........................................................................50
5.5.2. Fast Shut Down by Software ...........................................................................52
7. ANTENNA(S) ..................................................................................................61
GSM/WCDMA/TD-SCDMA/LTE Antenna Requirements ................................61
GSM/WCDMA/TD-SCDMA/LTE Antenna – PCB Line Guidelines ..................62
GSM/WCDMA/LTE Antenna – Installation Guidelines ....................................63
Antenna Diversity Requirements .....................................................................63
GNSS Antenna Requirements ........................................................................64
7.5.1. Combined GNSS Antenna ..............................................................................64
7.5.2. Linear and Patch GNSS Antenna ....................................................................65
7.5.3. Front End Design Considerations....................................................................65
7.5.4. GNSS Antenna – PCB Line Guidelines ...........................................................65
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1. Introduction
Scope
This document introduces the Telit LE910Cx module and presents possible and
recommended hardware solutions for developing a product based on the LE910Cx
module. All the features and solutions detailed in this document are applicable to all
LE910Cx variants, where “LE910Cx” refers to the variants listed in the applicability table.
NOTE:
LE910Cx refers to all modules listed in the Applicability Table.
This document takes into account all the basic functions of a wireless module; suggests a
valid hardware solution for each function and points out incorrect solutions and common
errors to be avoided.
Obviously, this document cannot embrace every hardware solution or every product that
can be designed. Obviously, avoiding invalid solutions must be considered mandatory.
Where the suggested hardware configurations need not be considered mandatory, the
information given should be used as a guide and a starting point for properly developing
your product with the Telit LE910Cx module.
NOTE:
The integration of the GSM/GPRS/EGPRS/WCDMA/HSPA+/LTE LE910Cx
cellular module within a user application must be done according to the
design rules described in this manual.
Audience
This document is intended for Telit customers, especially system integrators, about to
implement their applications using the Telit LE910Cx module.
For general contact, technical support services, technical questions and report
documentation errors, contact Telit Technical Support at:
• TS-EMEA@telit.com
• TS-AMERICAS@telit.com
• TS-APAC@telit.com
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Alternatively, use:
http://www.telit.com/support
For detailed information about where you can buy the Telit modules or for
recommendations on accessories and components visit:
http://www.telit.com
To register for product news and announcements or for product questions contact Telit’s
Technical Support Center (TTSC).
Our aim is to make this guide as helpful as possible. Keep us informed of your comments
and suggestions for improvements.
Text Conventions
DANGER:
Danger – This information MUST be followed, or catastrophic equipment
failure or bodily injury may occur.
WARNING:
Caution or Warning – Alerts the user to important points about integrating the
module, if these points are not followed, the module and end user equipment
may fail or malfunction.
NOTE:
Tip or Information – Provides advice and suggestions that may be useful
when integrating the module.
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Related Documents
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2. Product Description
Overview
NOTE:
(EN) The integration of the LE910Cx cellular module within user application
shall be done according to the design rules described in this manual.
(IT) L’integrazione del modulo cellulare LE910Cx all’interno dell’applicazione
dell’utente dovrà rispettare le indicazioni progettuali descritte in questo
manuale.
(DE) Die Integration des LE910Cx Mobilfunk-Moduls in ein Gerät muß gemäß
der in diesem Dokument beschriebenen Kunstruktionsregeln erfolgen.
(SL) Integracija LE910Cx modula v uporabniški aplikaciji bo morala upoštevati
projektna navodila, opisana v tem priročniku.
(SP) La utilización del modulo LE910Cx debe ser conforme a los usos para los
cuales ha sido deseñado descritos en este manual del usuario.
(FR) L’intégration du module cellulaire LE910Cx dans l’application de
l’utilisateur sera faite selon les règles de conception décrites dans ce manuel.
(HE)
The information presented in this document is believed to be accurate and reliable. However, no
responsibility is assumed by Telit Communications S.p.A. for its use, nor any infringement of patents
or other rights of third parties which may result from its use. No license is granted by implication or
otherwise under any patent rights of Telit Communications S.p.A. other than for circuitry embodied
in Telit products. This document is subject to change without notice.
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Applications
The LE910Cx series of cellular modules features an LTE and multi-RAT modem together
with a powerful on-chip application processor and a rich set of interfaces.
The major functions and features are listed below:
Function Features
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Function Features
Environment The entire module is designed and qualified by Telit for satisfying the
and quality environment and quality requirements.
requirements
Single supply The module generates all its internal supply voltages.
module
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Function Features
NOTE:
The following interfaces are unique for the LE910Cx and may not be
supported on other (former or future) xE910 family. Special care must be
taken when designing the application board if future compatibility is required:
- SGMII for Ethernet connectivity
- SDIO for WIFI connectivity
- SD/MMC for SD Card connectivity
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Block Diagram
MEMORIES
GNSS_Sync
SIM
PCM In/out
GNSS Antennna LOCATION
VBATT_PA
MODEM
Cellular antenna 1
RF
FRONTEND Cellular antenna 2
VBATT
APPLICATION PMIC
ADC
PROCESSOR RTC
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Environmental Requirements
As a part of the Telit corporate policy of environmental protection, the LE910Cx complies
with the RoHS (Restriction of Hazardous Substances) directive of the European Union
(EU directive 2011/65/EU).
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The operating frequencies in GSM850, EGSM900, DCS1800, PCS1900, WCDMA & LTE
modes conform to the 3GPP specifications.
Table 4 summarizes all region variants within the LE910Cx family, showing the supported
band sets in each variant.
Region
2G HSPA+ LTE FDD LTE TDD TD-SCDMA
Variant
LE910C1-NA 2, 3, 5, 8 1, 2, 4, 5, 8 2, 4, 12 - -
1, 3, 5, 8, 9, 18, 19,
LE910C1-AP - 1, 5, 6, 8, 19 - -
26, 28
1, 3, 5, 8, 9, 18, 19,
LE910C4-AP - 1, 5, 6, 8, 19 - -
26, 28
LE910C1-SV - - 4, 13 - -
LE910C1-LA 2, 3, 5, 8 1, 2, 4, 5 1, 2, 3, 4, 5, 7, 28 - -
LE910C4-LA 2, 3, 5, 8 1, 2, 4, 5 1, 2, 3, 4, 5, 7, 28 - -
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Tx-Rx
Mode Freq. Tx (MHz) Freq. Rx (MHz) Channels
Offset
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Tx-Rx
Mode Freq. Tx (MHz) Freq. Rx (MHz) Channels
Offset
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Tx-Rx
Mode Freq. Tx (MHz) Freq. Rx (MHz) Channels
Offset
Tx: 131972-132671
LTE AWS-3 – B66 1710 ~ 1780 2210 ~ 2200 400 MHz
Rx: 66436-67335
Tx: 133122-133471
LTE600 – B71 663 ~ 698 617 ~ 652 46 MHz
Rx: 68568-68935
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RF Parameters
2.7.1. Sensitivity
• 2G (GSM):
- LB: Class 4(2W, 33dBm)
Class E2(0.5W,27dBm@EDGE)
- HB: Class 1(1W, 30Bm)
Class E2(0.4W, 26dBm@EDGE)
• 3G (WCDMA): Class 3(0.25W, 24dBm)
• TD-SCDMA: Class 3(0.13W, 21dBm)
• 4G (FDD & TDD): Class 3(0.2W, 23dBm@1RB)
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Mechanical Specifications
2.8.1. Dimensions
NOTE:
LE910C1-SV’s thickness is only 2.3mm, +/- 0.15 mm tolerance.
NOTE:
Consider a typical label thickness of 0.1 mm in addition to the module
thickness.
2.8.2. Weight
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3. Module Connections
Pin-out
Table 6: Pin-out
See note
A14 USB_ID AI USB ID
below
Asynchronous UART
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LTE-WiFi Coexistence
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Internally PU
External SIM 1 signal - Data
A5 SIMIO1 I/O 1.8/2.85V 10 kΩ to
I/O
SIMVCC1
Internally PU
External SIM 2 signal – Data
C2 SIMIO2 I/O 1.8/2.85V 10kΩ to
I/O
SIMVCC2
Alternate Fn
C8 GPIO_01 I/O GPIO_01 / STAT_LED 1.8V
I2C
Alternate Fn
C9 GPIO_02 I/O GPIO_02 1.8V
I2C
Alternate Fn
C10 GPIO_03 I/O GPIO_03 1.8V
I2C
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Alternate Fn
C11 GPIO_04 I/O GPIO_04 1.8V
I2C
Alternate Fn
B14 GPIO_05 I/O GPIO_05 1.8V
I2C
Alternate Fn
C12 GPIO_06 I/O GPIO_06 1.8V
I2C
Alternate Fn
C13 GPIO_07 I/O GPIO_07 1.8V
I2C
Alternate Fn
K15 GPIO_08 I/O GPIO_08 / SW_RDY 1.8V
I2C
Alternate Fn
L15 GPIO_09 I/O GPIO_09 1.8V
I2C
Alternate Fn
G15 GPIO_10 I/O GPIO_10 1.8V
I2C
RF Section
GSM/EDGE/UMTS/LTE Main
K1 Antenna I/O RF
antenna (50 Ohm)
GPS Section
Miscellaneous Functions
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SGMII Interface
HSIC Interface
I2C Interface
Internally PU
B11 I2C_SCL I/O I2C clock 1.8V
2.2kΩ to 1.8V
Internally PU
B10 I2C_SDA I/O I2C Data 1.8V
2.2kΩ to 1.8V
Power Supply
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A2 GND - Ground
D4 GND - Ground
E1 GND - Ground
E2 GND - Ground
F2 GND - Ground
G1 GND - Ground
G2 GND - Ground
G7 GND - Ground
G8 GND - Ground
G9 GND - Ground
H1 GND - Ground
H2 GND - Ground
H7 GND - Ground
H8 GND - Ground
H9 GND - Ground
J1 GND - Ground
J2 GND - Ground
J7 GND - Ground
J8 GND - Ground
J9 GND - Ground
K2 GND - Ground
L1 GND - Ground
L2 GND - Ground
M3 GND - Ground
M4 GND - Ground
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N3 GND - Ground
N4 GND - Ground
N5 GND - Ground
N6 GND - Ground
P3 GND - Ground
P4 GND - Ground
P5 GND - Ground
P6 GND - Ground
P8 GND - Ground
P9 GND - Ground
R2 GND - Ground
R3 GND - Ground
R5 GND - Ground
R6 GND - Ground
R8 GND - Ground
Reserved
A8 Reserved - Reserved
A9 Reserved - Reserved
B2 Reserved - Reserved
B3 Reserved - Reserved
B4 Reserved - Reserved
B5 Reserved - Reserved
C3 Reserved - Reserved
C4 Reserved - Reserved
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C5 Reserved - Reserved
C6 Reserved - Reserved
C7 Reserved - Reserved
D3 Reserved - Reserved
D8 Reserved - Reserved
D9 Reserved - Reserved
E3 Reserved - Reserved
F3 Reserved - Reserved
G3 Reserved - Reserved
H3 Reserved - Reserved
J3 Reserved - Reserved
J4 Reserved - Reserved
K3 Reserved - Reserved
K4 Reserved - Reserved
L3 Reserved - Reserved
M5 Reserved - Reserved
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M6 Reserved - Reserved
M7 Reserved - Reserved
N7 Reserved - Reserved
N8 Reserved - Reserved
P7 Reserved - Reserved
NOTE:
When the UART signals are used as the communication port between the
host and the modem, the RTS must be connected to GND (on the module
side) if flow control is not used.
If the UART port is not used, all UART signals can be left disconnected.
NOTE:
Unless otherwise specified, RESERVED pins must be left unconnected
(floating).
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NOTE:
The following pins are unique for the LE910Cx and may not be supported on
other (former or future) xE910 family modules. Special care must be taken
when designing the application board if future compatibility is required.
REF_CLK
SPI_CS
USB_ID
I2C_SCL
I2C_SDA
ADC_IN2
ADC_IN3
Table 7 lists the LE910Cx signals that must be connected even if not used by the end
application:
VBATT &
M1, M2, N1, N2, P1, P2
VBATT_PA
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C4, C5, C6, C7, D3, E3, G3, P11 Reserved Connect to a Test Point for
Telit internal use
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The LE910Cx is fully backward compatible to the previous xE910 in terms of:
• Mechanical dimensions
• Package and pin-map
To support the extra features and additional interfaces, the LE910Cx introduces more pins
compared to the xE910.
The extra pins of the LE910Cx can be considered as optional if not needed and can be left
unconnected (floating) if not used.
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In this case, the new LE910Cx can be safely mounted on existing carrier boards designed
for the previous xE910.
The additional pins of the LE910Cx are shown in Figure 3 (marked as Green)
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4. Electrical Specifications
WARNING:
A deviation from the value ranges listed below may harm the LE910Cx
module.
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Unless otherwise specified, all the interface circuits of the LE910Cx are 1.8V CMOS logic.
Only few specific interfaces (such as MAC, USIM and SD Card) are capable of dual
voltage I/O.
The following tables show the logic level specifications used in the LE910Cx interface
circuits.
NOTE:
Do not connect LE910Cx digital logic signals directly to OEM digital logic
signals with a level higher than 2.7V for 1.8V CMOS signals.
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NOTE:
Pull-Up and Pull-Down resistance of GPIO3, GPIO7 and GPIO8 is different
than above mentioned
GPIO3 pull resistance is specified as 10KΩ to 50KΩ
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5. Hardware Commands
To turn on the LE910Cx module, the ON_OFF_N pad must be asserted low for at least 1
second and then released.
The maximum current that can be drained from the ON/OFF # pad is 0.1 mA. This pin is
internally pulled up; customers should expect to see ~ 800 mV on the output.
Figure 4 illustrates a simple circuit to power on the module using an inverted buffer output.
NOTE:
Recommended values R2 = 47 kΩ, R1 = 10 kΩ.
After turning on the LE910Cx module, a predefined internal boot sequence performs the
HW and SW initialization of the module, which takes some time to complete fully. During
this process, the LE910Cx is not accessible.
As shown in Figure 5, the LE910Cx becomes operational at least 20 seconds after the
assertion of ON_OFF.
NOTE:
During the Initialization state, AT commands are not available. The DTE host
must wait for the Activation state prior to communicating with the LE910Cx.
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VBATT
ON_OFF
NOTE:
SW_RDY signal is available on GPIO_08 (by default GPIO_08 functions as
SW_RDY)
NOTE:
To check whether the LE910Cx has completely powered on, monitor the
SW_RDY hardware line. When SW_RDY goes high, the module has
completely powered on and is ready to accept AT commands.
NOTE:
During SW initialization of the LE910Cx, the SW configures all pads and
interfaces to their desired mode. When PWRMON goes high, this indicates
that the initialization of all I/O pads is completed.
NOTE:
Do not use any pull-up resistor on the ON_OFF_N line as it is internally
pulled up. Using a pull-up resistor may cause latch-up problems on the
LE910Cx power regulator and improper powering on/off of the module. The
ON_OFF_N line must be connected only in an open-collector configuration.
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NOTE:
For systems not requiring controlled power ON/OFF, automatic power on can
be supported by shorting the ON_OFF signal directly GND
In this case, the module will start power on sequence immediately after
VBATT supply is applied
NOTE:
Active low signals are labeled with a name that ends with "#" or with “_N”
NOTE:
To avoid a back-powering effect, it is recommended to avoid having any
HIGH logic level signal applied to the digital pins of the module when it is
powered OFF or during an ON/OFF transition.
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Turning off the device can be done in the following different ways:
• Shutdown by software using AT#SHDN software command
• Hardware shutdown using ON_OFF_N pad
• Hardware Unconditional Shutdown using the SHDN_N pad
When the device is shut down by a software command or a hardware shutdown, it issues
a detach request to the network, informing the network that the device will not be
reachable anymore.
NOTE:
To check if the device has powered off, monitor the PWRMON hardware
line. When PWRMON goes low, this indicates that the device has powered
off.
NOTE:
To avoid a back-powering effect, it is recommended to avoid having any
HIGH logic level signal applied to the digital pins of the module when it is
powered OFF or during an ON/OFF transition.
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When a shutdown command is sent, LE910Cx goes into the Finalization state and at the
end of the finalization process shuts down PWRMON.
The duration of the Finalization state can differ according to the current situation of the
module, so a value cannot be defined.
Usually, it will take more than 10 seconds from sending a shutdown command until
reaching a complete shutdown. The DTE host should monitor the status of PWRMON to
observe the actual power-off.
NOTE:
To check whether the device has powered off, monitor the PWRMON
hardware line. When PWRMON goes low, the device has powered off.
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To turn off the LE910Cx module, the ON_OFF_N pad must be asserted low for at least
2.5 seconds and then released. Use the same circuitry and timing for power-on.
When the hold time of ON/OFF# is above 2.5 seconds, LE910Cx goes into the
Finalization state and eventually shuts down PWRMON.
The duration of the Finalization state can differ according to the current situation of the
module, so a value cannot be defined.
Usually, it will take more than 15 seconds from sending a shutdown command until
reaching a complete shutdown. The DTE host should monitor the status of PWRMON to
observe the actual power-off.
NOTE:
To check whether the device has powered off, monitor the PWRMON
hardware line. When PWRMON goes low, the device has powered off.
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To unconditionally shut down the LE910Cx module, the HW_SHUTDOWN_N pad must be
tied low for at least 200 milliseconds and then released.
Figure 8 shows a simple circuit for applying an unconditional shutdown.
SHDN_N
T_RDY ~0 Sec
SW_RDY
T_PWRMON ~0 Sec
V_AUX
PWRMON
NOTE:
Recommended values are as follows: R2 = 47kΩ, R1 = 10kΩ.
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NOTE:
Do not use any pull-up resistor on the HW_SHUTDOWN_N line or any totem
pole digital output. Using a pull-up resistor may cause latch-up problems on
the LE910Cx power regulator and improper functioning of the module. The
HW_SHUTDOWN_N line must be connected only in an open-collector
configuration.
NOTE:
The Unconditional Hardware Shutdown must always be implemented on the
boards, but the software must use it only as an emergency exit procedure,
and not as a normal power-off operation.
Powering OFF the module should be done gracefully allowing the module to complete all
ongoing and pending tasks while properly handling all memory buffers.
In the case where a complete power supply shut down is needed, the following procedure
should be followed:
1. Perform a HW shutdown as described in Section 5.3.1
2. Wait for the HW Shutdown procedure to complete (monitor the PWRMON pin).
WARNING:
Follow the recommended procedure for shut down and power off carefully.
Not following the recommended shut-down and power off procedures might
damage the device and consequently void the warranty.
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The graceful power down procedure is described in chapter 5.1 and 5.2. It normally takes
more than 15 seconds to de-attach network and make LE910Cx internal filesystem
properly closed.
In case of unwanted power supply loss, LE910Cx can be switched off without any risk of
filesystem data corruption by implementing Fast Power Down feature.
The Fast Power Down feature permits to reduce the current consumption and the time-to-
power off to minimum values.
NOTE:
Refer to LE910Cx series AT command reference guide (Fast power down -
#FASTSHDN) in order to set up detailed AT command.
The Fast Shut Down is triggered by a GPIO. Customers who want to implement the Fast
Shut Down should configure a GPIO as the trigger pin for the Fast Shut Down through AT
command. The high-to-low transition of a GPIO triggers the Fast Shut Down and then
LE910Cx module turns off within 30ms.
The following is the example hardware configuration for the Fast Shut Down.
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NOTE:
Consider voltage drop under max current conditions when defining the
voltage detector threshold in order to avoid unwanted shutdown.
The most important thing is that a system should give sufficient energy LE910Cx turns off
safely during 30ms after the Fast Shut Down is triggered. If not, unwanted memory
corruption can be happened. VAUX pin can be used to check if LE910Cx is turned off. If
VUAX is low, LE910Cx is turned off.
The following formula can be used to calculate Ctank value to give LE910Cx sufficient
energy during the Fast Shut Down.
LE910Cx consumes up to 800mA and 30ms is the typical time to execute the shutdown
and 1V is the minimum voltage margin from threshold of LE910Cx hardware reset. Based
on the formula, more than 24mF is needed for the Fast Shut Down.
But the Ctank value should be optimized depending on the detection voltage and load
current LE910Cx consumes in customer’s system.
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NOTE:
Make the same plot during system verification to check timings and voltages
levels.
WARNING:
Ctank associated with low ESR requires current limiting feature in DCDC
converter to avoid side effect of inrush current.
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6. Power Supply
The power supply circuitry and board layout are very important parts of the full product
design, with critical impact on the overall product performance. Read the following
requirements and guidelines carefully to ensure a good and proper design.
NOTE:
For PTCRB approval on the final products, the power supply is required to
be within the range of “Normal Supply voltage ranger”.
Power Consumption
Table 18 provides typical current consumption values of LE910Cx for the various available
modes.
Average
Mode Mode Description
(Typ.)
Switched Off
Switched off 25µA Module supplied but switched Off (RTC On)
2.6 mA DRx2
GSM
2.1 mA DRx5
DRX 2.1 mA DRx7
AT+CFUN=5
WCDMA
1.9 mA DRx8
LTE 2.4mA Paging cycle #128 frames (1.28 sec DRx cycle)
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Average
Mode Mode Description
(Typ.)
LTE (0dBm)
LTE CAT 1/CAT 4 channel BW 20 MHz,
RB=Full RB, Tx = 0 dBm
300mA With FTP TpT session LTE to USB
10Mbps DL/5Mbps UL (CAT 1)
150Mbps DL/50Mbps UL (CAT 4)
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Average
Mode Mode Description
(Typ.)
GPRS 2 Tx + 1 Rx
* Worst/best case current values depend on network configuration, not under module
control.
* The above idle mode currents are measured when Status LED turned off which is
controlled by AT#SLED. See the AT Command User Guide for details about the
AT#SLED section.
NOTE:
The electrical design for the power supply must ensure a peak current output
of at least 2.0A.
NOTE:
In GSM/GPRS mode, RF transmission is not continuous, but is packed into
bursts at a base frequency of about 216 Hz with relative current peaks as
high as about 2.0A. Therefore, the power supply must be designed to
withstand these current peaks without big voltage drops. This means that
both the electrical design and the board layout must be designed for this
current flow.
If the layout of the PCB is not well designed, a strong noise floor is
generated on the ground. This will reflect on all the audio paths producing an
audible annoying noise at 216 Hz.
If the voltage drops during the peaks, current absorption is too high. The
device may even shut down as a consequence of the supply voltage drop.
The principal guidelines for the Power Supply Design embrace three different design
steps:
• Electrical design
• Thermal design
• PCB layout
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The electrical design of the power supply depends strongly on the power source where
this power is drained. Power sources can be distinguished by three categories:
• +5V input (typically PC internal regulator output)
• +12V input (typically automotive)
• Battery
• The desired output for the power supply is 3.8V. So, the difference between the
input source and the desired output is not big, and therefore a linear regulator can
be used. A switching power supply is preferred to reduce power consumption.
• When using a linear regulator, a proper heat sink must be provided to dissipate the
power generated.
• A bypass low ESR capacitor of adequate capacity must be provided to cut the
current absorption peaks close to the LE910Cx module. A 100 μF tantalum
capacitor is usually suitable on both VBATT and VBATT_PA power lines.
• Make sure that the low ESR capacitor on the power supply output (usually a
tantalum one) is rated at least 10V.
• A protection diode must be inserted close to the power input to protect the
LE910Cx module from power polarity inversion.
• The desired output for the power supply is 3.8V. Due to the big difference between
the input source and the desired output, a linear regulator is unsuitable and must
not be used. A switching power supply is preferable because of its better
efficiency, especially with the 2A peak current load expected during GSM Tx.
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Figure 13 and Figure 14 show an example of switching regulator with 12V input.
• The desired nominal output for the power supply is 3.8V, and the maximum
allowed voltage is 4.2V. Hence, a single 3.7V Li-Ion cell battery type is suitable for
supplying the power to the LE910Cx module.
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NOTE:
Do not use any Ni-Cd, Ni-MH, and Pb battery types directly connected to the
LE910Cx module. Their use can lead to overvoltage on the LE910Cx and
damage it. Use only Li-Ion battery types.
• A bypass low ESR capacitor of adequate capacity must be provided to cut the
current absorption peaks; a 100μF tantalum capacitor is usually suitable.
• Make sure that the low ESR capacitor (usually a tantalum one) is rated at least
10V.
• A protection diode must be inserted close to the power input to protect the
LE910Cx module from power polarity inversion. Otherwise, the battery connector
must be done in a way to avoid polarity inversions when connecting the battery.
• The battery capacity must be at least 500 mAh to withstand the current peaks of
2A.
The thermal design for the power supply heat sink must be done with the following
specifications:
• Average current consumption during RF transmission @PWR level max in
LE910Cx as shown in Table 18: LE910Cx Current Consumption
• Average current consumption during Class10 GPRS transmission @PWR level
max as shown in Table 18: LE910Cx Current Consumption
• Average GPS current consumption during GPS tracking (LTE @ idle): mA (40mA)
NOTE:
The average consumption during transmission depends on the power level
at which the device is requested to transmit via the network. Therefore, the
average current consumption varies significantly.
NOTE:
The thermal design for the power supply must be made keeping an average
consumption at the max transmitting level during calls of (LTE/HSPA)/GPRS
plus average consumption in GPS Tracking mode.
Considering the very low current during Idle, especially if the Power Saving function is
enabled, it is possible to consider from the thermal point of view that the device absorbs
significant current only during an Active Call or Data session.
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For the heat generated by the LE910Cx module, consider it to be 2W max during
transmission at Class10 GPRS upload.
The LE910Cx is designed to conduct the heat flow from the module IC’s towards the
bottom of the PCB across GND metal layers
The generated heat is mostly conducted to the ground plane under the LE910Cx module.
The application board should be properly designed to dissipate this heat.
Application board design needs to make sure the area under the LE910Cx module is as
large as possible. Make sure that the LE910Cx is mounted on the large ground area of
application board and provide many ground vias to dissipate the heat.
As seen in the electrical design guidelines, the power supply must have a low ESR
capacitor on the output to cut the current peaks and a protection diode on the input to
protect the supply from spikes and polarity inversion. The placement of these components
is crucial for the correct operation of the circuitry. A misplaced component can be useless
or can even decrease the power supply performances.
• The bypass low ESR capacitor must be placed close to the LE910Cx power input
pads, or if the power supply is of a switching type, it can be placed close to the
inductor to cut the ripple, as long as the PCB trace from the capacitor to LE910Cx
is wide enough to ensure a drop-less connection even during the 2A current
peaks.
• The protection diode must be placed close to the input connector where the power
source is drained.
• The PCB traces from the input connector to the power regulator IC must be wide
enough to ensure that no voltage drops occur during the 2A current peaks.
Note that this is not done in order to avoid RF power loss but to avoid the voltage
drops on the power line at the current peaks frequency of 216 Hz that will reflect
on all the components connected to that supply (also introducing the noise floor at
the burst base frequency)
For this reason, while a voltage drop of 300-400 mV may be acceptable from the
RF power loss point of view, the same voltage drop may not be acceptable from
the noise point of view. If your application does not have an audio interface but
only uses the data feature of the LE910Cx, this noise is not so disturbing, and the
power supply layout design can be more forgiving.
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• The PCB traces to LE910Cx and the bypass capacitor must be wide enough to
ensure that no significant voltage drops occur when the 2A current peaks are
absorbed. This is needed for the same above-mentioned reasons. Try to keep
these traces as short as possible.
• The PCB traces connecting the switching output to the inductor and the switching
diode must be kept as short as possible by placing the inductor and the diode very
close to the power switching IC (only for the switching power supply). This is done
to reduce the radiated field (noise) at the switching frequency (usually 100-
500 kHz).
• Use a good common ground plane.
• Place the power supply on the board in a way to guarantee that the high current
return paths in the ground plane do not overlap any noise sensitive circuitry, such
as the microphone amplifier/buffer or earphone amplifier.
• The power supply input cables must be kept separate from noise sensitive lines,
such as microphone/earphone cables.
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7. Antenna(s)
Antenna connection and board layout design are the most important parts in the full
product design, and they have a strong influence on the product’s overall performance.
Read carefully and follow the requirements and guidelines for a good and proper design.
The antenna for the LE910Cx device must meet the following requirements:
Frequency range The customer must use the most suitable antenna bandwidth
for covering the frequency bands provided by the network
operator and supported by the OEM while using the Telit
module.
The bands supported by each variant of the LE910Cx module
family are provided in Section 2.6.1, RF Bands per Regional
Variant.
Impedance 50 Ohm
Since there is no antenna connector on the LE910Cx module, the antenna must be
connected to the LE910Cx antenna pad (AD1) by a transmission line implemented on the
PCB.
If the antenna is not directly connected to the antenna pad of the LE910Cx, a PCB line is
required to connect to it or to its connector.
Cold End (Ground Plane) of the antenna must be equipotential to the LE910Cx ground
pads.
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Furthermore, if the device is developed for the US and/or Canada market, it must comply
with the FCC and/or IC approval requirements:
This device is to be used only for mobile and fixed application. The antenna(s) used for this
transmitter must be installed to provide a separation distance of at least 20 cm from all persons and
must not be co-located or operating in conjunction with any other antenna or transmitter. End-Users
must be provided with transmitter operation conditions for satisfying RF exposure compliance. OEM
integrators must ensure that the end user has no manual instructions to remove or install the
LE910Cx module. Antennas used for this OEM module must not exceed 3dBi gain for mobile and
fixed operating configurations.
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• Install the antenna in a location with access to the network radio signal.
• The antenna must be installed such that it provides a separation distance of at
least 20 cm from all persons and must not be co-located or operating in
conjunction with any other antenna or transmitter.
• The antenna must not be installed inside metal cases.
• The antenna must be installed according to the antenna manufacturer’s
instructions.
This product includes an input for a second Rx antenna to improve radio sensitivity. The
function is called Antenna Diversity.
Frequency The customer must use the most suitable antenna bandwidth for
range covering the frequency bands provided by the network operator and
supported by the OEM while using the Telit module.
The bands supported by each variant of the LE910Cx module family
are provided in Section 2.6.1, RF Bands per Regional Variant
Impedance 50Ω
Since there is no antenna connector on the LE910Cx module, the antenna must be
connected to the LE910Cx antenna pad by means of a transmission line implemented on
the PCB.
If the antenna is not directly connected at the antenna pad of the LE910Cx (F1), a PCB
line is required to connect to it or to its connector.
The second Rx antenna must not be located in close vicinity of the main antenna. To
improve diversity gain and isolation and to reduce mutual interaction, the two antennas
should be located at the maximum reciprocal distance possible, taking into consideration
the available space within the application.
NOTE:
If Rx Diversity is not used/connected, disable the Diversity functionality using
the AT+XRXDIV command (refer to Ref 1: LE920x4/LE910Cx AT Command
User Guide) and connect the Diversity pad F1 to a 50 Ohm termination.
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NOTE:
80502ST10950A_LE910Cx AT_Commands_Reference_Guide document
must be referred to install passive or active GNSS ANT configuration by
customer.
NOTE:
The external GNSS pre-filter is required for the GLONASS application.
The GNSS pre-filter must meet the following requirements:
Source and load impedance = 50 Ohm
Insertion loss (1575.42–1576.42 MHz) = 1.4 dB (Max)
Insertion loss (1565.42–1585.42 MHz) = 2.0 dB (Max)
Insertion loss (1597.5515–1605.886 MHz) = 2.0 dB (Max)
NOTE:
It is recommended to add a DC block to the customer’s GPS application to
prevent damage to the LE910Cx module due to unwanted DC voltage.
NOTE:
It is recommended to add PI matching network near the GPS connector on
the application board in case that RF matching is needed.
The use of a combined RF/GNSS antenna is NOT recommended. This solution can
generate an extremely poor GNSS reception. In addition, the combination of antennas
requires an additional diplexer, which adds significant power loss in the RF path.
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Since there is no antenna connector on the LE910Cx module, the antenna must be
connected to the LE910Cx through the PCB to the antenna pad.
If the antenna is not directly connected at the antenna pad of the LE910Cx, a PCB line is
required.
Cold End (Ground Plane) of the antenna must be equipotential to the LE910Cx ground
pads.
Furthermore, if the device is developed for the US and/or Canada market, it must comply
with the FCC and/or IC requirements.
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8. Hardware Interfaces
Table 23 summarizes all the hardware interfaces of the LE910Cx module.
Interface LE910Cx
HSIC x1 (Optional)
ADC Up to x3
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USB Port
The LE910Cx module includes a Universal Serial Bus (USB) transceiver, which operates
at USB high-speed (480Mbits/sec). It can also operate with USB full-speed hosts
(12Mbits/sec).
It is compliant with the USB 2.0 specification and can be used for control and data
transfers as well as for diagnostic monitoring and firmware update.
The USB port is typically the main interface between the LE910Cx module and OEM
hardware.
NOTE:
The USB_D+ and USB_D- signals have a clock rate of 480 MHz. The signal
traces must be routed carefully. Minimize trace lengths, number of vias, and
capacitive loading. The impedance value should be as close as possible to
90 Ohms differential.
USB_VBUS A13 Power and cable detection for the internal USB transceiver.
Acceptable input voltage range 2.5V – 5.5V @ max 5 mA
consumption
USB_D- C15 Minus (-) line of the differential, bi-directional USB signal to/from
the peripheral device
USB_D+ B15 Plus (+) line of the differential, bi-directional USB signal to/from
the peripheral device
USB_ID A14 Used for USB OTG to determine host or client mode
NOTE:
USB_VBUS input power is internally used to detect the USB port and start
the enumeration process.
It is a power supply pin with a maximum consumption of 5 mA.
Do not use pull up or a voltage divider for sourcing this supply
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NOTE:
Even if USB communication is not used, it is still highly recommended to
place an optional USB connector on the application board.
At least test points of the USB signals are required since the USB physical
communication is needed in the case of SW update.
NOTE:
USB OTG support is optional and is not supported by default. An external
5V power supply is required on the application board for supporting USB
OTGץ
The application processor exposes a High-Speed Inter-Chip (HSIC). HSIC eliminates the
analog transceiver from a USB interface for lower voltage operation and reduced power
dissipation.
• High-speed 480 Mbps (240 MHz DDR) USB transfers are 100% host driver
compatible with traditional USB cable connected topologies
• Bidirectional data strobe signal (STROBE)
• Bidirectional data signal (DATA)
• No power consumption unless a transfer is in progress
SGMII Interface
The SOC includes an integrated Ethernet MAC with an SGMII interface, having the
following key features:
• The SGMII interface can be used connect to an external Ethernet PHY, or an
external switch.
• When enabled, an additional network interface will be available to the Linux kernel.
• Further details can be found at Ref 8: ETH_Expansion_board_Application Note
When using an external PHY for Ethernet connectivity, the LE910Cx also includes the
control interface for managing the external PHY
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NOTE:
The Ethernet control interface is shared with USIM2 port!
When Ethernet PHY is used, USIM2 port cannot be used (and vice versa).
NOTE:
ETH_INT_N is a 1.8V input. It has an internal pull up to 1.8V inside the
module thus it should be connected to an open drain interrupt pin of the
Ethernet PHY. In case the PHY does not support 1.8V I/O, proper level
shifter needs to be used.
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Serial Ports
The serial port is typically a secondary interface between the LE910Cx module and OEM
hardware. The following serial ports are available on the module:
• Modem Serial Port 1 (Main)
• Modem Serial Port 2 (Auxiliary)
Several serial port configurations can be designed for the OEM hardware. The most
common are:
• RS232 PC com port
• Microcontroller UART @ 1.8V (Universal Asynchronous Receive Transmit)
• Microcontroller UART @ 3.3V/5V or other voltages different from 1.8V
Depending on the type of serial port on OEM hardware, level translator circuits may be
needed to make the system operate. The only configuration that does not need level
translation is the 1.8V UART.
The LE910Cx UART has CMOS levels as described in Section 4.3, Logic Level
Specifications.
On the LE910Cx, Serial Port 1 is a +1.8V UART with 7 RS232 signals. It differs from the
PC-RS232 in the signal polarity (RS232 is reversed) and levels. Table 26 lists the signals
of LE910Cx Serial Port 1.
RS232
Signal Pad No. Name Usage
Pin#
Data
DTR - Input to LE910Cx that controls
4 M14 Terminal
DTR_UART the DTE READY condition
Ready
A2, B13,
5 GND Ground Ground
D4…
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RS232
Signal Pad No. Name Usage
Pin#
NOTE:
DCD, DTR, DSR, RI signals that are not used for UART functions can be
configured as GPIO using AT commands.
NOTE:
To avoid a back-powering effect, it is recommended to avoid having any
HIGH logic level signal applied to the digital pins of the module when it is
powered OFF or during an ON/OFF transition.
NOTE:
For minimum implementations, only the TXD and RXD lines need be
connected. The other lines can be left open provided a software flow control
is implemented.
NOTE:
According to V.24, Rx/Tx signal names refer to the application side;
therefore, on the LE910Cx side, these signal are in the opposite direction:
TXD on the application side will be connected to the receive line (here
named TXD/ RX_UART) of the LE910Cx serial port and vice versa for Rx.
NOTE:
The DTR pin is used to control the UART and system sleep
Pulling the DTR pin low prevents the UART and the entire module from
entering low power mode.
DTR can be left floating if not used (DTR is internally pulled high).
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On the LE910Cx, Serial Port 2 is a +1.8V UART with Rx and Tx signals only.
The UART functionality is shared with SPI, thus simultaneous use of SPI and UART is not
supported.
D15 TXD_AUX O Auxiliary UART (Tx Data to DTE) 1.8V Shared with
SPI_MOSI
E15 RXD_AUX I Auxiliary UART (Rx Data to DTE) 1.8V Shared with
SPI_MISO
NOTE:
To avoid a back-powering effect, it is recommended to avoid having any
HIGH logic level signal applied to the digital pins of the module when it is
powered OFF or during an ON/OFF transition.
NOTE:
The Auxiliary UART is used as the SW main debug console. It is required to
place test points on this interface even if not used.
The RS232 UART 16450, 16550, 16650 & 16750 chipsets accept signals with lower levels
on the RS232 side (EIA/TIA-562), allowing a lower voltage-multiplying ratio on the level
translator. Note that the negative signal voltage must be less than 0V and hence some
sort of level translation is always required.
The simplest way to translate the levels and invert the signal is by using a single chip-level
translator. There are a multitude of them, differing in the number of drivers and receivers
and in the levels (be sure to get a true RS232 level translator, not a RS485 or other
standards).
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By convention, the driver is the level translator from the 0-1.8V UART to the RS232 level.
The receiver is the translator from the RS232 level to 0-1.8V UART. To translate the
whole set of control lines of the UART, the following is required:
• 2 drivers
• 2 receivers
WARNING:
The digital input lines, operating at 1.8V CMOS levels, have absolute
maximum input voltage of 2.0V. The level translator IC outputs on the
module side (i.e. LE910Cx inputs) will cause damage to the module inputs if
the level translator is powered with +3.8V power.
So, the level translator IC must be powered from a dedicated +1.8V power
supply.
As an example, RS232 level adaption circuitry could use a MAXIM transceiver (MAX218).
In this case, the chipset is capable of translating directly from 1.8V to the RS232 levels
(example on 4 signals only).
NOTE:
In this case, the length of the lines on the application must be taken into
account to avoid problems in the case of high-speed rates on RS232.
The RS232 serial port lines are usually connected to a DB9 connector as shown in Figure
14. Signal names and directions are named and defined from the DTE point of view.
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Peripheral Ports
In addition to the LE910Cx serial ports, the LE910Cx supports the following peripheral
ports:
• SPI – Serial Peripheral Interface
• I2C - Inter-integrated circuit
• SD/MMC Card Interface
• SDIO Interface
NOTE:
SPI is supported only on the Linux side.
The LE910Cx module supports Master mode only and cannot be configured
as Slave mode.
E15 SPI_MISO I SPI data Master input Slave 1.8V Shared with
output RX_AUX
D15 SPI_MOSI O SPI data Master output Slave 1.8V Shared with
input TX_AUX
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The I2C can also be used externally by the end customer application.
In addition, SW emulated I2C functionality can be used on GPIO pins 1-10. Any GPIO
(among GPIO 1-10) can be configured as SCL or SDA.
NOTE:
SW emulated I2C on GPIO lines is supported only from the modem side. For
more information, refer to Ref 1: LE920x4/LE910Cx AT Command User
Guide for command settings.
NOTE:
To keep backward compatibility with previous LE910 products, it is
recommended to keep using the SW emulated I2C available on GPIO’s 1-10.
The LE910Cx provides an SD port supporting the SD3.0 specification, which can be used
to support standard SD/MMC memory cards with the following features:
• Interface with SD/MMC memory cards up to 32 GB
• Max clock @ 2.95V - 50 MHz SDR
• Max Data: 25 MB/s
• SD standard: HS-SDR25 at 2.95V
• Max clock @ 1.8V - 200 MHz SDR
• Max Data: 100 MB/s
• SD standard: UHS-SDR104 at 1.8 V
• Max clock @ 1.8V - 50 MHz DDR
• Max Data: 50 MB/s
• SD standard: UHS-DDR50 at 1.8 V
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External PS 3V VMMC
MicroSD 10 10 10 10 10
K K K K K
DATA2 SD/MMC_DATA2
DATA3 SD/MMC_DATA3
CMD SD/MMC_CMD
VDD
SD/MMC_CLK
VSS
DATA0 SD/MMC_DATA0
DATA1 SD/MMC_DATA1
MMC_CD
SD/MMC_CD
GND GND
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NOTE:
SD/MMC is supported only on the Linux side.
The power supply to the SD/MMC card is to be provided by the Host
application board. The LE910Cx does not provide a dedicated power supply
for the SD/MMC card.
VMMC Supply is limited to 50mA thus can only supply the MMC card
external pull-up resistors.
Pull-up resistors must be placed on the host application board.
The card detection input has an internal pull-up resistor.
VMMC can be used for enabling of the external power supply (LDO Enable
signal)
The LE910Cx provides an SDIO port supporting the SDIO3.0 specification, which can be
used to interface with a WiFi chipset (Qualcomm QCA65x4 chipset or other WiFi
solutions). The LE910Cx module includes an integrated SW driver to support the
Qualcomm QCA6574 chipset.
NOTE:
Qualcomm QCA9377 WiFi chipset may be supported on some of the
LE910Cx variants.
Please contact your Telit representative for more details.
The LE910Cx SDIO port supports the SDIO 3.0 specification at 1.8V CMOS only, thus
cannot be used as an external SD/MMC card connection.
The LE910Cx module supports an LTE/WiFi coexistence mechanism via the WCI
(Wireless Coexistence Interface) port, which connects between the module and the
external WiFi IC.
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Audio Interface
The LE910Cx module can be connected to an external codec through the digital interface.
The product provides a single Digital Audio Interface (DVI) on the following pins:
In addition to the DVI port, the LE910Cx module provides a master clock signal
(REF_CLK on Pin B12) which can either provide a reference clock to an external codec or
form an I2S interface together with the DVI port where the REF_CLK acts as the
I2S_MCLK.
When using the DVI with REF_CLK as an I2S interface, 12.288 MHz is 256 x fs (where fs
= 48 kHz)
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The general-purpose I/O pads can be configured to act in three different ways:
• Input
• Output
• Alternative function (internally controlled)
Input pads can only be read, reporting digital values (high / low) present on the pad at the
reading time. Output pads can only be written or queried and set values on the pad
output. Alternative function pads can be internally controlled by LE910Cx firmware and act
according to the implementation.
The following GPIOs are always available as a primary function on the LE910Cx.
WARNING:
GPIO’s marked with (*) should not be pulled high externally (by the carrier
board) during module power on procedure. Pulling those pads high during
module power up might lead to unwanted/non-operational boot mode.
The additional GPIOs below can be used in case their initial functionality is not used:
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Alternate
PAD Signal I/O Initial Function Type Note
Function
WARNING:
GPIO’s marked with (*) should not be pulled high externally (by the carrier
board) during module power on procedure. Pulling those pads high during
module power up might lead to unwanted/non-operational boot mode.
NOTE:
LE910Cx GPIOs 1~10 can also be used as alternate I2C function. Refer to
Section 8.5.2, I2C - Inter-integrated Circuit.
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GPIO pads, when used as inputs, can be connected to a digital output of another device
and report its status, provided this device has interface levels compatible with the 1.8V
CMOS levels of the GPIO.
If the digital output of the device is connected with the GPIO input, the pad has interface
levels different from the 1.8V CMOS. It can be buffered with an open collector transistor
with a 10 kΩ pull-up resistor to 1.8V.
GPIO pads that are used as input can also be used as an interrupt source for the
software. In general, all GPIO pads can be also used as interrupts. However, not all
GPIO’s can be used as a wakeup source of the module (wakeup from sleep).
Only the following GPIO’s can be used for waking up the system from sleep:
• GPIO1
• GPIO4
• GPIO5
• GPIO8
GPIO pads, when used as outputs, can drive 1.8V CMOS digital devices or compatible
hardware. When set as outputs, the pads have a push-pull output, and therefore the pull-
up resistor can be omitted.
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9. Miscellaneous Functions
The STAT_LED pin status shows information on the network service availability and call
status. In the LE910Cx module, the STAT_LED usually needs an external transistor to
drive an external LED.
The STAT_LED does not have a dedicated pin. The STAT_LED functionality is available
on GPIO_01 pin (by default GPIO_01 functions as STAT_LED)
See the AT Command User Guide for details about the AT#SLED section.
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The SW_RDY signal provides indication about the ability of the module to receive
commands. As long as the SW_RDY is asserted low, it indicates that the LE910Cx has
not yet finished booting. Once the SW_RDY is asserted high, it indicates that the
LE910Cx is ready to receive commands.
The SW_RDY does not have a dedicated pin. The SW_RDY functionality is available on
GPIO_08 pin (by default GPIO_08 functions as SW_RDY).
The RTC within the LE910Cx module does not have a dedicated RTC supply pin. The
RTC block is supplied by the VBATT supply.
A regulated power supply output is provided to supply small devices from the module.
This output is active when the module is ON and goes OFF when the module is shut
down. The operating range characteristics of the supply are as follows:
ADC Converter
9.5.1. Description
The LE910Cx module provides three on-board 8-bit Analog to Digital converters. Each
ADC reads the voltage level applied on the relevant pin, converts it and stores it into an 8-
bit word.
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AD conversion - 8 bits
Refer to Ref 1: LE920x4/LE910Cx AT Command User Guide for the full description of this
function.
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GNSS Characteristics
Table 39 specifies the GNSS characteristics and expected performance. The values are
related to typical environment and conditions.
Typical
Parameters Notes
Measurement
Standalone or MS Based
-162.3 dBm
Tracking Sensitivity
Sensitivity
Acquisition -157.5 dBm
Cold Start Sensitivity -157.5 dBm
GPS+GLONASS
Hot 1.1s
Simulator test
GPS+GLONASS
TTFF Warm 22.1s
Simulator test
GPS+GLONASS
Cold 29.94s
Simulator test
GPS+GLONASS
Accuracy 0.8 m
Simulator test
Min Navigation update rate 1Hz
Dynamics 2g
Operation limits 515 m/sec
A-GPS Supported
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General
The below figure shows the mechanical dimensions of the LE910Cx module.
4 x Route
Inhibit
Lead-free Alloy:
Surface finishing Ni/Au for all solder pads
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Figure 26 shows the recommended footprint for the application board (dimensions are in
mm).
NOTE:
In the customer application, the region marked as INHIBIT WIRING in Figure
26 must be clear of signal wiring or ground polygons.
4 x Route
Inhibit
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Stencil
Stencil’s apertures layout can be the same as the recommended footprint (1:1). The
suggested thickness of stencil foil is greater than 120 µm.
The solder pads on the PCB are recommended to be of the Non-Solder Mask Defined
(NSMD) type.
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It is not recommended to place around the pads a via or micro-via that is not covered by
solder resist in an area of 0.15 mm unless it carries the same signal as the pad itself. Micro
via inside the pads are allowed.
Holes in pad are allowed only for blind holes and not for through holes.
The PCB must be able to resist the higher temperatures, which occur during the lead-free
process. This issue should be discussed with the PCB-supplier. Generally, the wettability
of tin-lead solder paste on the described surface plating is better compared to lead-free
solder paste.
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Solder Paste
We recommend using only “no clean” solder paste to avoid the cleaning of the modules
after assembly.
WARNING:
The above solder reflow profile represents the typical SAC reflow limits and
does not guarantee adequate adherence of the module to the customer
application throughout the temperature range. Customer must optimize the
reflow profile depending on the overall system taking into account such
factors as thermal mass and warpage
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Preheat
– Temperature min (Tsmin) 150°C
– Temperature max (Tsmax) 200°C
– Time (min to max) (ts) 60-180 seconds
Tsmax to TL
– Ramp-up rate 3°C/second max
NOTE:
All temperatures refer to the top side of the package, measured on the
package body surface.
WARNING:
The LE910Cx module withstands one reflow process only.
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10.7.2. Cleaning
In general, cleaning the module mounted on the carrier board is not recommended.
• Residues between module and host board cannot be easily removed with any
cleaning method.
• Cleaning with water or any organic solvent can lead to capillary effects where the
cleaning solvent is absorbed into the gap between the module and the host board
or even leak inside the module (due to the gap between the module shield and
PCB) . The combination of soldering flux residues and encapsulated solvent could
lead to short circuits between conductive parts. The solvent could also damage the
module label.
• Ultrasonic cleaning could damage the module permanently. Especially for crystal
oscillators where the risk of damaging is very high.
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To test and debug the mounting of the LE910Cx module, we strongly recommend adding
several test pads on the application board design for the following purposes:
• Checking the connection between the LE910Cx itself and the application
• Testing the performance of the module by connecting it with an external computer
Depending on the customer application, these test pads include, but are not limited to the
following signals:
• TXD
• RXD
• ON/OFF
• HW_SHUTDOWN_N
• GND
• VBATT
• TX_AUX
• RX_AUX
• USB_VBUS
• USB_D+
• USB_D-
• GPIO_09
• WCI_RX
In addition, the following signals are also recommended (but not mandatory):
• PWRMON
• GPIO_01 (STAT_LED)
• GPIO_08 (SW_RDY)
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When a sudden voltage step to or a cut from the power supplies is asserted, the steep
transition causes some reactions such as overshoot and undershoot. This abrupt voltage
transition can affect the device causing it to not operate or to malfunction.
Bypass capacitors are needed to alleviate this behaviour. The behaviour can appear
differently depending on the various applications. Customers must pay special attention to
this issue when they design their application board.
The length and width of the power lines must be considered carefully, and the capacitance
of the capacitors must be selected accordingly.
The capacitor will also prevent ripple of the power supplies and the switching noise
caused in TDMA systems, such as GSM.
Especially, a suitable bypass capacitor must be mounted on the following lines on the
application board:
• VBATT & VBATT_PA (M1, M2, N1, N2, P1, P2)
• USB_VBUS (Pad A13)
Customers must still consider that the capacitance mainly depends on the conditions of
their application board.
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SIM Interface
This section presents the recommended schematics for the design of SIM interfaces on
the application boards. The LE910Cx supports two external SIM interfaces.
Figure 30 illustrates in particular how to design the application side and what values to
assign the components.
NOTE:
The resistor value on SIMIO pulled up to SIMVCC must be defined to be
compliant with the 3GPP specification for USIM electrical testing.
The LE910Cx module contains an internal pull-up resistor of 10K Ω on
SIMIO.
However, the un-mounted R1 option in the application can be used to tune
SIMIO timing if necessary.
LE910Cx 100 nF
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EMC Recommendations
All LE910Cx signals are provided with some EMC protection. Nevertheless, the accepted
level differs according to the specific pin. Table 43 lists the characteristics.
All Pins
Antenna
Appropriate series resistors must be considered to protect the input lines from overvoltage.
Choose one of the following options in the design of host system to download or upgrade
the Telit software and debug the LE910Cx module when it is already mounted on a host
system.
• UART and USB interfaces
Users who use both UART and USB interfaces to communicate with the LE910Cx
module must implement a USB download method in the host system to upgrade
the LE910Cx when it is mounted.
Users who use a USB interface only to communicate with the LE910Cx module
must arrange for a USB port in the host system to debug or upgrade the LE910Cx
when it is mounted.
Users who use a UART interface only to communicate with the LE910Cx module
must arrange for a UART port in the host system to debug or upgrade the
LE910Cx when it is mounted.
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Fastboot is triggered by GPIO_09 (PAD L15). Asserting this signal high (1.8V) during boot
will force the system into Fastboot
Emergency boot download mode is used in case of corrupted boot image was flashed into
the device or in case all other recovery modes failed to work
Emergency download mode is triggered by WCI_RX signal (PAD M9). Asserting this
signal high (1.8V) during boot will force the system into Emergency download.
NOTE:
The application board must support accessible test pads on GPIO_09 and
WCI_RX signal to enable the download recovery modes mentioned above.
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The LE910Cx modules are packaged on trays of 36 pieces each as shown in Figure 31.
These trays can be used in SMT processes for pick & place handling.
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Moisture Sensitivity
The LE910Cx module is a Moisture Sensitive Device Level 3, in accordance with standard
IPC/JEDEC J-STD-020. Observe all of the requirements for using this kind of
components.
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Be sure that the use of this product is allowed in your country and in the environment
required. The use of this product may be dangerous and must be avoided in the following
areas:
• Where it can interfere with other electronic devices in environments such as
hospitals, airports, aircrafts, etc.
• Where there is risk of explosion, such as gasoline stations, oil refineries, etc.
It is the responsibility of the user to enforce the country regulations and the specific
environment regulations.
Do not disassemble the product; any mark of tampering will compromise the warranty
validity.
We recommend following the instructions of the hardware user guides for correct wiring of
the product. The product must be supplied with a stabilized voltage source and the wiring
conform to the security and fire prevention regulations.
The product must be handled with care, avoiding any contact with the pins because
electrostatic discharges may damage the product itself. The same caution must be taken
for the SIM, checking carefully the instructions for its use. Do not insert or remove the SIM
when the product is in power saving mode.
The system integrator is responsible for the functioning of the final product; therefore, care
must be taken of the external components of the module, as well as of any project or
installation issue, because of the risk of disturbing the cellular network or external devices
or having any impact on safety. Should there be any doubt, refer to the technical
documentation and the regulations in force.
Every module must be equipped with a proper antenna with the specified characteristics.
The antenna must be installed with care to avoid any interference with other electronic
devices and must be installed with the guarantee of a minimum 20 cm distance from a
human body. If this requirement cannot be satisfied, the system integrator must assess
the final product against the SAR regulation.
The European Community provides some Directives for electronic equipment introduced
on the market. All the relevant information is available on the European Community
website:
http://europa.eu.int/comm/enterprise/rtte/dir99-5.htm
The text of the Directive 99/05 regarding telecommunication equipment is available, while
the applicable Directives (Low Voltage and EMC) are available at:
http://europa.eu.int/comm/enterprise/rtte/dir99-5.htm
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The following statement must be included with all versions of this document supplied to an
OEM or integrator but should not be distributed to the end user.
2) Please see the full Grant of Equipment document for other restrictions
The OEM integrator has to be aware not to provide information to the end user regarding
how to install or remove this RF module in the user’s manual of the end product which
integrates this module. The end user manual shall include all required regulatory
information/warming as shown in this manual
This equipment must be installed and operated in accordance with provided instructions
and the antenna(s) used for this transmitter must be installed to provide a separation
distance of at least 20 cm from all persons and must not be co-located or operating in
conjunction with any other antenna or transmitter. End-users and installers must be
provide with antenna installation instructions and consider removing the no-collocation
statement
The module has been evaluated in mobile stand-alone conditions. For different
operational conditions from a stand-alone modular transmitter in a host (multiple,
simultaneously transmitting modules or other transmitters in a host), additional testing
may be required (collocation, retesting…) If this module is intended for use in a portable
device, you are responsible for separate approval to satisfy the SAR requirements of FCC
Part 2.1093 and IC RSS-102
The modular transmitter is only FCC authorized for the specific rule parts (i.e., FCC
transmitter rules) listed on the grant, and that the host product manufacturer is responsible
for compliance to any other FCC rules that apply to the host not covered by the modular
transmitter grant of certification. If the grantee markets their product as being Part 15
Subpart B compliant (when it also contains unintentional-radiator digital circuity), then the
grantee shall provide a notice stating that the final host product still requires Part 15
Subpart B compliance testing with the modular transmitter installed. The end product with
an embedded module may also need to pass the FCC Part 15 unintentional emission
testing requirements and be properly authorized per FCC Part 15
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Modification Statement
Telit has not approved any changes or modifications to this device by the user. Any
changes or modifications could void the user’s authority to operate the equipment.
Telit n’approuve aucune modification apportée à l’appareil par l’utilisateur, quelle qu’en
soit la nature. Tout changement ou modification peuvent annuler le droit d’utilisation de
l’appareil par l’utilisateur.
Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils
radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes : (1)
l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter
tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en
compromettre le fonctionnement.
Wireless Notice
This device complies with FCC/ISED radiation exposure limits set forth for an uncontrolled
environment and meets the FCC radio frequency (RF) Exposure Guidelines and RSS‐102
of the ISED radio frequency (RF) Exposure rules. Antenna gain must be below:
1700 MHz 1700 5.00 5.00 5.00 6.00 13.0 5.00 5.00
700 MHz 700 5.63 5.63 5.94 6.44 N/A 5.63 5.63
This transmitter must not be co-located or operating in conjunction with any other antenna
or transmitter.
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Le présent appareil est conforme à l'exposition aux radiations FCC / ISED définies pour
un environnement non contrôlé et répond aux directives d'exposition de la fréquence de la
FCC radiofréquence (RF) et RSS‐102 de la fréquence radio (RF) ISED règles
d'exposition. Gain de l'antenne doit être ci-dessous:
1700 MHz 1700 5.00 5.00 5.00 6.00 13.0 5.00 5.00
700 MHz 700 5.63 5.63 5.94 6.44 N/A 5.63 5.63
L'émetteur ne doit pas être colocalisé ni fonctionner conjointement avec à autre antenne
ou autre émetteur.
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LE910C1 NA
Contains FCC ID: RI7LE910C1NA
LE910C1 NS
Contains FCC ID: RI7LE910C1NS
LE910C1/C4 NF
Contains FCC ID: RI7LE910CXNF
LE910C1 SV
Contains FCC ID: RI7LE910C1SV
LE910C1 SA
Contains FCC ID: RI7LE910C1SA
LE910C1 ST
Contains FCC ID: RI7LE910C1ST
LE910C1/C4 LA
Contains FCC ID: RI7LE910CXLA
L'appareil hôte doit être étiqueté comme il faut pour permettre l'identification des modules
qui s'y trouvent. L'étiquette de certification du module donné doit être posée sur l'appareil
hôte à un endroit bien en vue en tout temps. En l'absence d'étiquette, l'appareil hôte doit
porter une étiquette donnant le FCC ID et le IC du module, précédé des mots « Contient
un module d'émission », du mot « Contient » ou d'une formulation similaire exprimant le
même sens, comme suit:
LE910C1 NA
Contains FCC ID: RI7LE910C1NA
LE910C1 NS
Contains FCC ID: RI7LE910C1NS
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LE910C1/C4 NF
Contains FCC ID: RI7LE910CXNF
LE910C1 SV
Contains FCC ID: RI7LE910C1SV
LE910C1 SA
Contains FCC ID: RI7LE910C1SA
LE910C1 ST
Contains FCC ID: RI7LE910C1ST
LE910C1/C4 LA
Contains FCC ID: RI7LE910CXLA
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Antenna
According to Japan regulatory rule, module certification is valid only with the specific
antennas registered to and approved by JRL certified body in relation to module
certification. Customers who are going to use modules under Japan Radio Law, are
responsible to contact Telit technical support or sales to get the list of these antennas.
Dial Function
The JTBL Module Certification for “LE910C1-AP” is for “non-Auto Redial Function” device.
In case customer implement “Auto Redial” function into Application Device by controlling
LE910C1-AP, the customer cannot utilize LE910C1-AP JTBL certification, and they must
apply JTBL as “Application Device” System.
According to NCC Taiwan requirements, the module and the packaging shall be
identified as described in the following lines. Shall be added also the specified safety
warning statement.
NCC logo:
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15. Acronyms
AE Application-enabled
SD Secure digital
SMX SmartMX
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SOC System-on-Chip
AE Application-enabled
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SD Secure digital
SOC System-on-Chip
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1.10 2017-12-27 General spelling and grammar edits throughout the document
Section 2.3 – Updated features list table.
Section 2.4 - Fixed typo in section and inside block diagram.
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1.04 2017-05-25 Section 14.1 – Added Labelling Requirements for the Host
device
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