Applications information

TDA7498L

20/27

Doc ID 16504 Rev 3

5.3

Gain setting

The gain of the TDA7498L is set by the two inputs, GAIN0 (pin 30) and GAIN1 (pin 31).

Internally, the gain is set by changing the feedback resistors of the amplifier.

5.4

Input resistance and capacitance

The input impedance is set by an internal resistor Ri = 60 k

Ω (typical). An input capacitor

(Ci) is required to couple the AC input signal.

The equivalent circuit and frequency response of the input components are shown in

Figure 23. For Ci = 470 nF the high-pass filter cutoff frequency is below 20 Hz:

Figure 23.

Input circuit and frequency response

Table 8.

Gain settings

GAIN0

GAIN1

LL

25.6

LH

31.6

HL

35.6

HH

37.6

Ri

Input

Ci

Rf

Input

pin

signal