Tfa9842aj PDF
Tfa9842aj PDF
Tfa9842aj PDF
1. General description
The TFA9842AJ contains two identical audio power amplifiers. The TFA9842AJ can be
used as two Single-Ended (SE) channels with a volume control. The maximum gain is
26 dB.
The TFA9842AJ comes in a 9-pin DIL-bent-SIL (DBS9P) power package. The TFA9842AJ
is pin compatible with the TFA9843AJ, TFA9843(B)J, TFA9842(B)J and TFA9841J. The
difference between the TFA9843AJ and the TFA9843(B)J, TFA9842(B)J, TFA9841J is the
functionality of pin 7. The TFA9843AJ has a Volume Control (VC) on pin 7. The
TFA9843(B)J, TFA9842(B)J and TFA9841J have a mode select (MODE) on pin 7.
The TFA9842AJ contains a unique protection circuit that is solely based on multiple
temperature measurements inside the chip. This gives maximum output power for all
supply voltages and load conditions with no unnecessary audio holes. Almost any supply
voltage and load impedance combination can be made as long as thermal boundary
conditions (number of channels used, external heatsink and ambient temperature) allow
it.
2. Features
n 2 channel SE: 1 W to 7.5 W operation possibility
n Soft clipping
n Input clamps
n Volume control
n Standby and Mute mode
n No on or off switching plops
n Low standby current
n High supply voltage ripple rejection
n Outputs short-circuit protected to ground, supply and across the load
n Thermally protected
n Pin compatible with the TFA9843AJ, TFA9843(B)J, TFA9842(B)J and TFA9841J
3. Applications
n CRT TV and LCD TV
n Monitors
n PC speakers
n Boom box
n Mini and micro audio receivers
Philips Semiconductors TFA9842AJ
7.5 W stereo power amplifier with volume control
5. Ordering information
Table 2. Ordering information
Type number Package
Name Description Version
TFA9842AJ DBS9P plastic DIL-bent-SIL power package; 9 leads (lead SOT523 -1
length 12/11 mm); exposed die pad
6. Block diagram
VCC
9
4 8
IN1 OUT1
60
kΩ
1 2
IN2 OUT2
60
kΩ
3 SHORT-CIRCUIT
CIV AND
TEMPERATURE
VREF
PROTECTION
VCC
7 VOLUME
VC
CONTROL
0.5VCC 6
SVR
TFA9842AJ
5
001aae064
GND
7. Pinning information
7.1 Pinning
IN2 1
OUT2 2
CIV 3
IN1 4
GND 5 TFA9842AJ
SVR 6
VC 7
OUT1 8
VCC 9
001aae063
8. Functional description
1
f i ( –3dB ) = ----------------------------- (1)
2π ( R i × C i )
1
f i ( –3dB ) = ----------------------------------------------------------------
3 –9
- = 12 Hz (2)
2π ( 60 × 10 × 220 × 10 )
As shown in Equation 2, large capacitor values for the inputs are not necessary; therefore
switch-on delay during charging of the input capacitors can be minimized. This results in a
good low frequency response and good switch-on behavior.
The TFA9842AJ has clamps on the inputs. In Standby mode the voltage on the input pins
is clamped for voltages lower than −0.1 V. When the TFA9842AJ is in Mute, Volume
control or Operating mode (maximum gain) the input clamp voltage is 1 V (RMS).
8.2.2 Headroom
Typical CD music requires at least 12 dB (factor 15.85) dynamic headroom, compared to
the average power output, for transferring the loudest parts without distortion. At
VCC = 17 V and Po = 5 W (SE with RL = 4 Ω) at THD < 0.5 % (see Figure 5), the Average
Listening Level (ALL) music power without any distortion yields:
5
P o ( ALL ) = ------------- = 315 mW (3)
15.85
The power dissipation can be derived from Figure 8 (SE) for 0 dB respectively 12 dB
headroom (see Table 4).
For the average listening level a power dissipation of 4.2 W can be used for a heatsink
calculation.
The protection will only be activated when necessary, so even during a short-circuit
condition, a certain amount of (pulsed) current will still flow through the short-circuit (as
much as the power stage can handle without exceeding the critical temperature level).
9. Limiting values
Table 6. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol Parameter Conditions Min Max Unit
VCC supply voltage operating −0.3 +28 V
VI input voltage −0.3 VCC + 0.3 V
IORM repetitive peak output - 3 A
current
Tstg storage temperature non-operating −55 +150 °C
Tamb ambient temperature operating −40 +85 °C
Ptot total power dissipation - 35 W
VCC(scp) short-circuit protection - 26 V
supply voltage
[1] The noise output voltage is measured at the output in a frequency range from 20 Hz to 22 kHz
(unweighted), with a source impedance ZS = 0 Ω at the input.
[2] Supply voltage ripple rejection is measured at the output, with a source impedance ZS = 0 Ω at the input
and with a frequency range from 20 Hz to 22 kHz (unweighted). The ripple voltage is a sine wave with a
frequency fripple and an amplitude of 300 mV (RMS), which is applied to the positive supply rail.
[3] Output voltage in Mute mode (VI(VC) = 1.35 V) and an input voltage of 1 V (RMS) in a bandwidth from 20 Hz
to 22 kHz, so including noise.
001aae340 001aaa445
50 40
GV Po
(dB) (W)
0 30
−50 20
2Ω 3Ω 4Ω
−100 10 RL = 1 Ω 8Ω
−150 0
0 2.0 4.0 6.0 8 12 16 20 24 28
VI(VC) (V) VCC (V)
VCC = 17 V THD = 10 %
Fig 3. Voltage gain as a function of volume control Fig 4. Output power (one channel) as a function of
voltage supply voltage for various SE loads
001aaa419 001aaa446
102 10
THD+N
(%) THD+N
(%)
10
1
10−1
10−1
10−2 10−2
10−1 1 10 102 10 102 103 104 105
Po (W) f (Hz)
001aaa447 001aaa422
15 10
Po PD
(W) (W)
12 8
9 6
6 4
3 2
0 0
8 10 12 14 16 18 0 4 8 12 16 20
VCC (V) Po (W)
001aaa423 001aaa424
0 0
αcs
SVRR
(dB) (dB)
−20
−20
−40
−40
−60
−60
−80
−100 −80
10 102 103 104 105 10 102 103 104 105
f (Hz) f (Hz)
VCC
VCC 100 nF 1000 µF
9
220 nF
IN1 4 8 OUT1
Vi 1000 µF +
RL
60 kΩ
4Ω
−
220 nF
IN2 1 2 OUT2
1000 µF
−
+
Vi RL
60 kΩ
4Ω
−
SHORT-CIRCUIT
CIV 3 AND
TEMPERATURE
VREF
PROTECTION
VCC
VC 7 VOLUME
CONTROL
22 µF 150 µF
001aae065
GND
Remark: Switching inductive loads, the output voltage can rise beyond the maximum
supply voltage of 28 V. At high supply voltage it is recommended to use (Schottky) diodes
to the supply voltage and ground.
VCC
R1
10 kΩ
T1
D1
5V
5.6 V
R2 R3
GND 1 kΩ 1 kΩ
R4
VC
1 kΩ
T3
C1
PWM R5 10 µF
T2
3.3 V 1 kΩ
001aae337
VCC
R1
10 kΩ
T1
R4 R5
PWM D1
VC 10 V
VC
5V 1 kΩ 16 kΩ
C1 R6 C1
10 µF 16 kΩ 10 µF
001aae338 001aae339
Fig 13. Volume control drive circuit with 5 V Fig 14. Volume control drive circuit with
PWM potentiometer
BTL1/2
1000 µF
100 nF
1000 µF
−SE1+
1000 µF
220
220 nF
nF
SVR
−SE2+
150 µF
SVR
CIV
MODE
22
µF SGND 10
+VP kΩ
10 kΩ
CIV
IN2+ IN1+ SB ON
MUTE
001aaa426
For suppressing higher frequency transients (spikes) on the supply line a capacitor with
low ESR, typical 100 nF, has to be placed as close as possible to the device. For
suppressing lower frequency noise and ripple signals, a large electrolytic capacitor, e.g.
1000 µF or greater, must be placed close to the device.
The bypass capacitor connected to pin SVR reduces the noise and ripple on the mid rail
voltage. For good THD and noise performance a low ESR capacitor is recommended.
Tamb(max) = 60 °C (example)
VCC = 17 V and RL = 4 Ω (SE)
Tj(max) = 150 °C (specification)
Rth(tot) is the total thermal resistance between the junction and the ambient including the
heatsink. This can be calculated using the maximum temperature increase divided by the
power dissipation:
P × Rth(tot) = 90 °C
Rth(tot) = 90/8.4 K/W = 10.7 K/W
Rth(h-a) = Rth(tot) − Rth(j-mb) = 10.7 K/W − 2.0 K/W = 8.7 K/W
P × Rth(tot) = 90 °C
Rth(tot) = 90/4.2 K/W = 21.4 K/W
Rth(h-a) = Rth(tot) − Rth(j-mb) = 21.4 K/W − 2.0 K/W = 19.4 K/W
001aaa449
150
RL = 2 Ω 4Ω 6Ω
Tj
8Ω
(°C)
100 16 Ω
50
0
8 12 16 20 24 28
VCC (V)
DBS9P: plastic DIL-bent-SIL power package; 9 leads (lead length 12/11 mm); exposed die pad SOT523-1
q1
non-concave
x
Eh
Dh
D
D1 view B: mounting base side
P A2
k
q2
E B
L3
L2
L1
L
1 9
Z e1 w M Q c v M
bp
e m e2
0 5 10 mm
2.7 0.80 0.58 13.2 6.2 14.7 3 12.4 11.4 6.7 4.5 3.4 1.15 17.5 1.65
mm 3.5 3.5 2.54 1.27 5.08 2.8 4.85 3.8 0.8 0.3 0.02
2.3 0.65 0.48 12.8 5.8 14.3 2 11.0 10.0 5.5 3.7 3.1 0.85 16.3 3.6 1.10
Notes
1. Plastic or metal protrusions of 0.25 mm maximum per side are not included.
2. Plastic surface within circle area D1 may protrude 0.04 mm maximum.
00-07-03
SOT523-1
03-03-12
16. Soldering
Wave soldering is the preferred method for mounting of through-hole mount IC packages
on a printed-circuit board.
The total contact time of successive solder waves must not exceed 5 seconds.
The device may be mounted up to the seating plane, but the temperature of the plastic
body must not exceed the specified maximum storage temperature (Tstg(max)). If the
printed-circuit board has been pre-heated, forced cooling may be necessary immediately
after soldering to keep the temperature within the permissible limit.
[1] For SDIP packages, the longitudinal axis must be parallel to the transport direction of the printed-circuit
board.
[2] For PMFP packages hot bar soldering or manual soldering is suitable.
[1] Please consult the most recently issued document before initiating or completing a design.
[2] The term ‘short data sheet’ is explained in section “Definitions”.
[3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.semiconductors.philips.com.
20. Contents
1 General description . . . . . . . . . . . . . . . . . . . . . . 1 19 Contact information . . . . . . . . . . . . . . . . . . . . 17
2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 20 Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
4 Quick reference data . . . . . . . . . . . . . . . . . . . . . 2
5 Ordering information . . . . . . . . . . . . . . . . . . . . . 2
6 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3
7 Pinning information . . . . . . . . . . . . . . . . . . . . . . 3
7.1 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
7.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 4
8 Functional description . . . . . . . . . . . . . . . . . . . 4
8.1 Input configuration . . . . . . . . . . . . . . . . . . . . . . 4
8.2 Power amplifier . . . . . . . . . . . . . . . . . . . . . . . . . 4
8.2.1 Output power measurement . . . . . . . . . . . . . . . 4
8.2.2 Headroom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.3 Mode selection . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.4 Supply voltage ripple rejection . . . . . . . . . . . . . 5
8.5 Built-in protection circuits . . . . . . . . . . . . . . . . . 6
9 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . . 6
10 Thermal characteristics. . . . . . . . . . . . . . . . . . . 6
11 Static characteristics. . . . . . . . . . . . . . . . . . . . . 7
12 Dynamic characteristics . . . . . . . . . . . . . . . . . . 7
13 Application information. . . . . . . . . . . . . . . . . . 10
13.1 Application diagrams . . . . . . . . . . . . . . . . . . . 10
13.1.1 Single-ended Application . . . . . . . . . . . . . . . . 10
13.1.2 Volume control drive options. . . . . . . . . . . . . . 11
13.2 Printed-circuit board . . . . . . . . . . . . . . . . . . . . 11
13.2.1 Layout and grounding . . . . . . . . . . . . . . . . . . . 11
13.2.2 Power supply decoupling . . . . . . . . . . . . . . . . 12
13.3 Thermal behavior and heatsink calculation . . 12
14 Test information . . . . . . . . . . . . . . . . . . . . . . . . 13
14.1 Quality information . . . . . . . . . . . . . . . . . . . . . 13
15 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 14
16 Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
16.1 Introduction to soldering through-hole mount
packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
16.2 Soldering by dipping or by solder wave . . . . . 15
16.3 Manual soldering . . . . . . . . . . . . . . . . . . . . . . 15
16.4 Package related soldering information . . . . . . 15
17 Revision history . . . . . . . . . . . . . . . . . . . . . . . . 16
18 Legal information. . . . . . . . . . . . . . . . . . . . . . . 17
18.1 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 17
18.2 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
18.3 Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
18.4 Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.