TDA7491MV

Application information

Doc ID 14576 Rev 2

21/28

7.2

Gain setting

The gain of the TDA7491MV 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.

7.3

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 21. For Ci = 220 nF the high-pass filter cut-off frequency is below 20 Hz:

fc = 1 / (2 *

π * Ri * Ci)

Figure 21.

Device input circuit and frequency response

Table 8.

Gain settings

GAIN0

GAIN1

0020

0126

1030

1132

Ri

Input

Ci

Rf

Input

pin

signal