Applications information
TDA7492
6.2
Gain setting
The gain of the TDA7492 is set by the two inputs, GAIN0 (pin 30) and GAIN1 (pin31).
Internally, the gain is set by changing the feedback resistors of the amplifier.
GAIN0
0
0
1
1
Table 7. Gain settings
GAIN1
0
1
0
1
Nominal gain, Gv (dB)
21.6
27.6
31.1
33.6
6.3
Input resistance and capacitance
The input impedance is set by an internal resistor Ri = 60 k (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 31. For Ci = 470 nF the high-pass filter cutoff frequency is below 20 Hz:
fc = 1 / (2 * * Ri * Ci)
Figure 31. Device input circuit and frequency response
Rf
Input
signal
Ci
Input Ri
pin
24/32
DocID014926 Rev 6