Service manual

Model no.:CT-21CBS5CPH.doc
version 1.0
35
2. TFA9842AJ
2-channel audio amplifier with volume control (SE: 1 W to 7.5 W)
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 heat sink
and ambient temperature) allow it.
2. Features
■
2 Channel SE: 1 W to 7.5 W operation possibility
■
Soft clipping
■
Input clamps
■
Volume control
■
Standby and mute mode
■
No on/off switching plops
■
Low standby current
■
High supply voltage ripple rejection
■
Outputs short-circuit protected to ground, supply and across the load
■
Thermally protected
■
Pin compatible with the TFA9843AJ, TFA9843(B)J, TFA9842(B)J, TFA9841J.
3. Applications
■
CRT TV, LCD TV
■
Monitors
■
PC speakers
■
Boom box
■
Mini and micro audio receivers.