TDA4350X Datasheet, PDF (7/32 Pages) Siemens Semiconductor Group – Audioprocessor

TDA 4350X
Loudness function starting at vol. a
increasing to ∆, following constant ∆.
Figure 6
3. In the following signalpath there is tone control, consisting of bass and treble control.
Bass control offers a control range of + 16 dB to – 14 dB with a stepwidth of 2 dB.
Frequency characteristic, 1st order or 2nd order (resonance type) is fixed by external
components. Treble control also offers a control range of + 16 dB to – 14 dB with a
stepwidth of 2 dB. The treble control corner frequency is determinated by an external
capacitor.
A second clipping detector allows to detect clipping in tone control part.
4. Last stages in signal path are four strictly independent controllable output attenuators
to realize balance and fader function. Each unit offers a control range of 0 dB to
– 38.75 dB in steps of 1.25 dB. The AF outputs are of a class A-type to avoid
distortion via software, the output fan-out can be increased to drive loads up
to > 1.5 kΩ.
One output of each stereo channel can be inverted software controlled, to drive easily
bridge power amplifiers.
5. Mute control may be either done via the volume control setting, or directly for all
outputs by setting the IM (immediately mute) bit via I²C Bus. The second bus
controlled mute mode is mute after signal zero crossing (ZCM). Two zero cross
detectors are built-in, therefore this mute control works independent for left and right
channel. Signal off- and on-switching is performed under zero cross detector control.
The ZCM status can be read out via I²C Bus (ZCS). After activating ZCM, the ZCS
(zero crossing status) bit is set to ‘1’, when all outputs are muted after zero crossing.
After deactivating ZCM, the ZCS bit is set to ‘0’ when all outputs are switched on after
zero crossing. The IM mute overwrites ZCM mute. Third mute control is hardware
mute via a mute pin. If the mute pin is switched to ground all outputs are muted
immediately. Hardware mute overwrites all other mute modes.
Semiconductor Group
7
04.96