PS224 Datasheet
PS224 Datasheet
PS224 Datasheet
Version : A.004
Issue Date : 2005/08/19
File Name : SP-PS224-A.004.doc
Total Pages : 11
PS224
4-Channel Secondary Monitoring IC
General Description
PS224 is specially designed for switching power supply system. Four important
functions of PS224 are the followings: over-voltage protection, over-current protection,
under-voltage protection and power good signal generating.
OVP/UVP (Over-Voltage/Under-Voltage Protection) monitors 3.3V, 5V and dual
12V to protect our power supply and PC, FPO/ goes to high when one of these supply
voltages exceeds their normal operation voltage range.
OCP (Over Current Protection) monitors IS33, IS5, IS12A, IS12B input current
sense. An adjustable over-current condition composed of Iref and “protection current
range resistor” helps users design OCP easily.
An additional protection input pin provides the flexibility for design protection
circuit.
Power good signal generating notifies personal computer when power supply is
ready or power supply is going to shutdown, therefore it can provide a reliable power
supply environment.
Features
• Over/Under-voltage protection and lock out
• Over-current protection and lock out
• Additional protection input
• Fault protection output with open drain output stage
• Open drain power good output signal for power good input
• Built-in 300mS power good delay
• AC on 75ms delay for UV/OC protection
• 38mS PSON/ control de-bounce
• Wide power supply range (3.8V~16V)
• Special care for AC power off
Block Diagram
VS12A
159KΩ
12 UV delay FPO/
S Q
5KΩ Vref
14uS R
12 OV 1MΩ
4.5V 90KΩ
VS5
64.5KΩ
5 UV
10KΩ Vref
VCCI
3.3 OV
Iref X 8
Timing Chart
Vcc
PSON/
FPO/
PGI
VS12A IS12A
VS12B IS12B
VS5 IS5
VS33 IS33
Pext
PGO
Td1 Tb1
Td3
Td2
VPGI 1.25V
1.25V
0.63V
Td1
Td2
Pin Descriptions
Over-Voltage Section
Parameter Conditions MIN TYP MAX Unit
VS33 3.8 3.9 4.0 V
Over-Voltage Threshold VS5 5.6 5.8 6.0 V
VS12A/B 13.5 14.0 14.2 V
Under-Voltage Section
Parameter Conditions MIN TYP MAX Unit
VS33 2.8 2.9 3.0 V
Under-Voltage Threshold VS5 4.2 4.4 4.6 V
VS12A/B 10.3 10.8 11.0 V
Over-Current Section
Parameter Conditions MIN TYP MAX Unit
Offset Voltage VS33/VS5 -5 0 3 mV
(OCP Comparator) VS12A/B -5 0 1 mV
Constant Current Generator Voltage (VRI) 1.20 1.25 1.30 V
Application
RS33
+3.3V Coil +3.3V Output
RS12(1)
+12V(1) Coil +12V(1) Output
RS12(2)
+12V(2) Coil +12V(2) Output
ROC12(2)
ROC12(1)
ROC33
ROC5
= or
4.7K
RPGO
1 PGI PGO 16 PGO
5 IS12A VS12A 12
Cby
6 RI IS33 11
7 IS12B IS5 10
RPGI
RI
PS224
Notes:
1. Zener diode or resistor or both of them can be used in component X.
2. The bypass capacitor Cby suggests to be 0.1uF~ 10uF and layout nearby pin VCC.
3. The recommend sense values of RS12(1), RS12(2), RS5 and RS33 are ≥ 0.002Ω.
4. Over-Current Protection design example:
= 62.5 K (Ω )
V 1.25
(1) I ref = 20 μA , RI = RI =
I RI 20μ
(2) RS5=0.002 Ω , ΔV5V = 0.002 × I +5V = ROC 5 × 8 × I ref
0.002 × 20
(3) If +5V OCP trip point is 20A, ROC 5 = = 250(Ω )
8 × 20 μ
Package Specification
( 16-pin DIP )
E1 E eB
θ°
A2 A
Seating Plane
A1 L
b1 b e S
0 5 10 15 20 25 mm
Package Specification
( 16-pin SOP )
E H
h x 45°
A C
A1
θ
B e
L
Seating Plane
0 5 10 mm
The products listed herein are designed for ordinary electronic applications, such as
electrical appliances, audio-visual equipment, communications devices and so on.
Hence, it is advisable that the devices should not be used in medical instruments,
surgical implants, aerospace machinery, nuclear power control systems,
disaster/crime-prevention equipment and the like. Misusing those products may
directly or indirectly endanger human life, or cause injury and property loss.
Silicon Touch Technology, Inc. will not take any responsibilities regarding the
misusage of the products mentioned above. Anyone who purchases any products
described herein with the above-mentioned intention or with such misused
applications should accept full responsibility and indemnify. Silicon Touch Technology,
Inc. and its distributors and all their officers and employees shall defend jointly and
severally against any and all claims and litigation and all damages, cost and
expenses associated with such intention and manipulation.
Silicon Touch Technology, Inc. reserve the right to make changes to their products or
to discontinue any product or service without notice, and advise customers to obtain
the latest version of relevant information to verify, before placing orders, that
information being relied on is current and complete.