TDA7294
APPLICATION SUGGESTIONS (see Test and ApplicationCircuits of the Fig. 1)
The recommended values of the external components are those shown on the application circuit of Fig-
ure 1. Different values can be used; the following table can help the designer.
LARGER THAN
SUGGESTED
SMALLER THAN
SUGGESTED
COMPONENTS
SUGGESTED VALUE
PURPOSE
R1 (*)
22k
INPUT RESISTANCE
INCREASE INPUT
IMPRDANCE
DECREASE INPUT
IMPEDANCE
R2
R3 (*)
R4
680Ω
22k
CLOSED LOOP GAIN DECREASE OF GAIN INCREASE OF GAIN
SET TO 30dB (**)
INCREASE OF GAIN DECREASE OF GAIN
22k
ST-BY TIME
CONSTANT
LARGER ST-BY
ON/OFF TIME
SMALLER ST-BY
ON/OFF TIME;
POP NOISE
R5
C1
10k
MUTE TIME
CONSTANT
LARGER MUTE
ON/OFF TIME
SMALLER MUTE
ON/OFF TIME
0.47µF
INPUT DC
DECOUPLING
HIGHER LOW
FREQUENCY
CUTOFF
C2
22µF
FEEDBACK DC
DECOUPLING
HIGHER LOW
FREQUENCY
CUTOFF
C3
C4
10µF
10µF
MUTE TIME
CONSTANT
LARGER MUTE
ON/OFF TIME
SMALLER MUTE
ON/OFF TIME
ST-BY TIME
CONSTANT
LARGER ST-BY
ON/OFF TIME
SMALLER ST-BY
ON/OFF TIME;
POP NOISE
C5
22µF
BOOTSTRAPPING
SIGNAL
DEGRADATION AT
LOW FREQUENCY
C6, C8
C7, C9
1000µF
0.1µF
SUPPLY VOLTAGE
BYPASS
DANGER OF
OSCILLATION
SUPPLY VOLTAGE
BYPASS
DANGER OF
OSCILLATION
(*) R1 = R3 FOR POP OPTIMIZATION
(**) CLOSED LOOP GAIN HAS TO BE ≥ 24dB
5/16
STMICROELECTRONICS [ ST ]
