Datasheet

Applications information TDA7493
18/30 Doc ID 14570 Rev 6
5.8.1 Single-ended input application
To use the device with a single-ended source, one input is AC connected to ground (via a
capacitor) and the other input is connected to the audio source. This is designed as a fully
differential input. The input scheme is shown in Figure 12.
However, to avoid the start-up pop noise, it is important to equalize, as much as possible,
the charging currents in the positive and negative inputs. Any imbalance in these charging
currents will be amplified and result in the familiar turn-on pop.
Figure 12. Single-ended input application
Since the input charging currents in the circuit of Figure 12 can be different it is necessary to
add two resistors, R0, as shown in the circuit of Figure 13. In this way the currents in the two
branches of the differential input are better balanced and this can lead to the elimination of
the turn-on pop noise.
Figure 13. Anti-pop configuration for single-ended input application
GND
cin
cin
TDA7493
Input stage
-
+
Audio Source
OUTP INP
INN
Rin
Rin
Rfb
Rfb
Cin
Cin
GND
Cin
Cin
TDA7493
Input stage
-
+
Audio Source
OUTP INP
INN
Rin
Rin
Rfb
Rfb
R0
R0