akira CT-21CDP5CPT, Service Manual

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Model no.:CT-21CDP5CPT.doc
version 1.0
32
2 TFA9842AJ
2-channel audio amplifier with volume control (SE: 1 W to 7.5 W)
2.1 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
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.
2.2 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
2.3 Block diagram of TFA9842AJ