TDA7476 Просмотр технического описания (PDF) - STMicroelectronics

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производитель

TDA7476

CAR RADIO DIAGNOSTIC PROCESSOR

STMicroelectronics 

TDA7476

The following table shows the result pointed out by TDA7476 when multiple misconnections are present:

ACTUAL FAULTS

POINTED OUT FAULT

S.C. CH+ to GND + OPEN LOAD

S.C. to GND

S.C. CH(*) to GND + S.C. ACROSS LOAD

S.C. to GND

S.C. CH- to GND + OPEN LOAD

OPEN LOAD

S.C. CH(*) to VS + OPEN LOAD

S.C. to VS

S.C. CH(*) to VS + S.C. ACROSS LOAD

S.C. to VS

S.C. CH+ to VS + S.C. CH- to GND

S.C. to VS

S.C. CH- to VS + S.C. CH+ to GND

S.C. to GND + S.C. to VS

(*) CH means CH+ or CH-

AUX1 - AUX2

s Voltage across the sensing resistors

S.C. to GND x Normal Operation x

Open Load

VS

0.85V 0.5V

125mV 85mV

0V

D97AU572A

s The minimum voltage of the AUX IN pin to sense the open load condition is 2V.

s The minimum voltage of the AUX IN pin to detect the short circuit to GND, by sensing the drop on the

resistors is 4.5V. If this voltage falls below 2V, the AUX in is considered short circuited to GND. From

2V to 4.5V the sensing circuit can detect a short circuit in both ways (by sensing across the resistor or

through the voltage between the AUX IN pin and GND).

PERMANENT DIAGNOSTIC - THRESHOLDS

CH1, CH2, CH3, CH4, CH5

s The circuit will recognize as a fault condition any situation where the following short circuit voltages last

more than 2 sec (typ).

s Output voltage

S.C. to GND x Normal Operation x

S.C. to Vs

0V

0.8V 1.2V

VS-1.2 VS-0.6V

VS

D97AU573B

AUX1 - AUX2

s The voltage across the resistors Rsens1 or Rsens2 is sensed. The circuit will recognize as a fault

condition any situation where the following voltages last more than 2sec (typ) in the region "S.C.to GND"

or "open load".

S.C. to GND x Normal Operation x

Open Load

VS

0.85V 0.5V

125mV 85mV

0V

D97AU574A

9/19

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