TDA7476

·WIDE OPERATINGVOLTAGE RANGE
·ST-BY FUNCTION (C-MOS)
·LOW QUIESCENT ST-BY CURRENT CONSUMPTION
·I²C BUS INTERFACE WITH 2 EXTERNALLY SELECTABLE ADDRESSES
·UP TO 5 BTL EQUIVALENT INPUTS FOR FAULT DETECTION IN THE AUDIO CHANNELS
   - short to GND
   - short to Vs
   - short across the load (at turn-on)
   - open load (at turn-on)
·2 AUX INPUTS FOR FAULT DETECTION IN THE ANTENNA AND BOOSTERS SUPPLY LINE
   - short to GND
   - open load
·WARNING PIN FUNCTION (interrupt facility) ACTIVATED IN THE FOLLOWING CONDITION:
   - audio channel shorted to VS
   - audio channel shorted to GND
   - aux input shorted to GND
·NOISE FREE DIAGNOSTICS OPERATION

·On single-ended devices as in figure 6, 7 if the loads are present then both in turn-on and in permanent diagnostic the fault present on one channel is pointed out for all the loads connected together. For example:
   - see fig.6 ifCH1+ is shortedto ground,theTDA7476 revealsa short to groundboth forCH2 and forCH1.
   - seefig.7ifCH1+is shortedto ground, theTDA7476detectsa short circuit togroundforCH1,CH2, CH3, CH4.
·To use the TDA7476 with a car-radio system which has less than five audio channel and less than two auxiliary loads, it is necessary to take some cares:
   - each pin CH+/- not used has to be fixed to 5V
   - each pin AUX1IN, AUX1OUT, AUX2IN, AUX2OUT not used has to be fixed to a voltage equal or greater than 5V.
   The 5V voltage reference available on the chip (pin 10) is very useful to fix both CH+/- and AUX pins to 5V.

The car radio diagnostic processor TDA7476 is an interface chip in BCD Technology intended for car radioapplications. It is able to detect potential faults coming from any misconnection in the car radio or in the harness when installing the set.

The TDA7476 is able to reveal any fault in the loudspeaker lines and in the antenna and booster supply lines, providing a proper output signal (I²C bus compatible) in order to disable the ICs under fault and/or to alert mcontroller by means of warning messages.