Datasheet

Applications information TDA7293
10/21 Doc ID 6744 Rev 8
4 Applications information
4.1 Applications suggestions
The recommended values of the external components are those shown on the application
circuit of Figure 1 on page 1. Different values can, however, be used and the following table
could be useful when choosing alternative values.
Figure 7. Slave function: pin 4 (Ref to pin 8)
Table 5. Choosing alternative component values
Component
Suggested
value
Purpose
Larger than
suggested
Smaller than
suggested
R1
(1)
1. R1 = R3 for pop optimization
22 kΩ Input resistance
Increase input
impedance
Decrease input
impedance
R2 680 Ω
Closed loop gain,
set to 30 dB
(2)
2. Closed loop gain has to be ³ 26dB
Decrease of gain Increase of gain
R3
(1)
22 kΩ Increase of gain Decrease of gain
R4 22 kΩ Standby time constant
Larger Standby
on/off time
Smaller standby
ON/OFF time; pop
noise
R5 10 kΩ Mute time constant
Larger mute
on/off time
Smaller mute
on/off time
C1 0.47 µF Input DC decoupling -
Higher low-frequency
cutoff
C2 22 µF
Feedback DC
decoupling
-
Higher low-frequency
cutoff
C3 10 µF Mute time constant
Larger mute
on/off time
Smaller mute on/off
time
C4 10 µF Standby time constant
Larger standby
on/off time
Smaller standby on/off
time; pop noise
C5 22 µF
(3)
x N
3. Multiply this value by the number, N, of modular parts connected
Bootstrapping -
Signal degradation at
low frequency
C6, C8 1000 µF Supply voltage bypass - -
C7, C9 0.1 µF Supply voltage bypass - Danger of oscillation
MASTER
UNDEFINED
SLAVE
-V
S
+3V
-V
S
+1V
-V
S
D98AU821
Note: If in the application the speakers are
connected via long wires, it is a good rule
to add, between the output and GND, a
boucherot cell in order to avoid dangerous
spurious oscillations if the speakers
terminal are shorted.
The suggested boucherot resistor is
3.9
Ω /2W and the capacitor is 1 µ F.