TDA7416 Datasheet, PDF (9/27 Pages) STMicroelectronics – CARRADIO SIGNAL PROCESSOR

TDA7416
1.1.1 Pseudo-differential stereo Input (IN1)
The IN1-input is implemented as a buffered pseudo-differential stereo stage with 100kΩ input-impedance
at each input pin. This input is also configurable as single-ended stereo input . The common input-pin, IN1-
features a fast charge switch to speed up the charge time of external capacitors.- This switch is released
the first time the input-selector data-byte (0) is assessed.
1.1.2 Single-ended stereo Inputs
All single ended inputs have an input impedance of 100kΩ.
1.2 AutoZero
The AutoZero allows a reduction of the number of pins as well as external components by canceling any
offset generated by or before the In-Gain-stage (Please notice that externally generated offsets, e.g. gen-
erated through the leakage current of the coupling capacitors, are not canceled).
The auto-zeroing is started every time the DATA-BYTE 0 is selected and needs max. 0.3ms for the align-
ment. To avoid audible clicks the Audioprocessor have to be muted by softmute or hard mute during this
time.
1.2.1 AutoZero-Remain
In some cases, for example if the µP is executing a refresh cycle of the IIC-Bus-programming, it is not
useful to start a new AutoZero-action because no new source is selected and an undesired mute would
appear at the out-puts. For such applications the TDA7416 could be switched in the AutoZero-Remain-
Mode (Bit 6(I1) of the subad-dress-byte). If this bit is set to high, the DATABYTE 0 could be loaded without
invoking the AutoZero and the old adjustment-value remains.
1.3 Loudness
There are four parameters programmable in the loudness stage:
1.3.1 Attenuation
Figure 2 shows the attenuation as a function of frequency at f_P = 400Hz
Figure 2. Loudness Attenuation @ f_P = 400Hz.
0.0
-5.0
-10.0
dB
-15.0
-20.0
-25.0
10.0
100.0
1.0K
Hz
10.0K
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