Datasheet

Application information TDA7491HV
34/41 Doc ID 14242 Rev 6
7.2 Gain setting
The gain of the TDA7491HV 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.
1. Refer to VinL and VinH in Table 5: Electrical specifications on page 10 for drive levels for L and H
7.3 Input resistance and capacitance
The input impedance is set by an internal resistor Ri = 68 kΩ (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 53. For Ci = 220 nF the high-pass filter cutoff frequency is below 20 Hz:
fc = 1 / (2 * π * Ri * Ci)
Figure 53. Device input circuit and frequency response
Table 8. Gain settings
GAIN0 GAIN1 Nominal gain, G
v
(dB)
L(1) H(1) 20
LH26
HL 30
HH32
Ri
Input
Ci
Rf
Input
pin
signal