Applications information
TDA7498L
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.
Table 8.
Gain settings
GAIN0
GAIN1
Nominal gain, Gv (dB)
L
L
25.6
31.6
35.6
37.6
L
H
L
H
H
H
5.4
Input resistance and capacitance
The input impedance is set by an internal resistor Ri = 60 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 23. For Ci = 470 nF the high-pass filter cutoff frequency is below 20 Hz:
f = 1 / (2 * π * Ri * Ci)
C
Figure 23. Input circuit and frequency response
Rf
Input
signal
Input
pin
Ri
Ci
20/27
Doc ID 16504 Rev 3
STMICROELECTRONICS [ ST ]
