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

-

+

OUTP

INP

INN

Rin

Rin

Rfb

Rfb

Cin

Cin

GND

Cin

Cin

TDA7493

Input stage

-

+

OUTP

INP

INN

Rin

Rin

Rfb

Rfb

R0

R0