TDA7406 Datasheet, PDF (17/64 Pages) STMicroelectronics – Car radio signal processor

TDA7406
Figure 3. Input-stages
Description of the audioprocessor part
4.2
4.2.1
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. generated 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 alignment. To avoid audible clicks the Audioprocessor have to be muted by soft mute
or hard mute during this time.
AutoZero for Stereodecoder-Selection
A special procedure is recommended for selecting the stereodecoder at the input-selector to
guarantee an optimum offset-cancellation:
(Step 0: SoftMute or Mute the signal-path)
Step 1: Temporary deselect the stereodecoder at the input-selector
Step 2: Configure the stereodecoder via IIC-Bus
Step 3: Wait 1ms
Step 4: Select the stereodecoder
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