TDA7493 datasheet(19/30 Pages) STMICROELECTRONICS

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TDA7493

Applications information

Doc ID 14570 Rev 6

19/30

The disadvantages of the anti-pop configuration are given below:

The input impedance or the load of audio source is no longer 2 * Rin as in the case of

differential input configuration but R0. It means the load effect should be considered

during the application design. At this point, bigger R0 is better because of the lower

load effect.

The input signal is also equivalent to

Vin_actual = Vin * 2 * Rin * (Rin + Rfb + R0) / (2 * Rin * (Rin + Rfb + R0) + Rfb * R0), not

the original Vin which means the actual gain is reduced.

When Rin = 30 k

Ω, Rfb = 30 kΩ and R0 = 20 kΩ, the gain is reduced by 1 dB.

When Rin = 30 k

Ω, Rfb = 120 kΩ and R0 = 20 kΩ, the gain is reduced by 1.84 dB. In

this case, smaller R0 is better.

If the pop noise is not critical, the anti-pop configuration can be simplified as shown in

Figure 14. The suggested value of the resistor R0 is 20 k

Ω.

Figure 14.

Simple anti-pop configuration for single-ended input application

GND

Cin

TDA7493

Input stage

OUTP

INP

INN

Rin

Rfb

TDA7493 데이터시트(PDF) 19 Page - STMicroelectronics