E-TDA7476 STMicroelectronics, E-TDA7476 Datasheet - Page 13

• Manufacturer Part Number: E-TDA7476
• Description: IC PROCESSOR RADIO DIAGN 24-SOIC
• Manufacturer: STMicroelectronics
• Type: Audio Processorr

Specifications of E-TDA7476

• Applications: Automotive Audio
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (7.5mm Width)
• Operating Temperature (min): -40C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

READ BYTE 1
READ BYTE 2
READ BYTE 3
Repetitive turn-on diagnostic
During the turn-on diagnostic, the TDA7476 can reveal false "short circuit across load" and/or false "open load"
due to noise sources such as door slams.
This problem can be solved doing more than one turn-on diagnostic routine. If the P asks for N times the state
of the audio system, it has to consider a fault as really present only if it is detected in all the N turn-on diagnos-
tic.As above explained, the first time the TDA7476 receivers the byte ADD1, it does the turn-on diagnostic; then
each time it is addessed with ADD1, it does the permanent diagnostic. This is not true if, when the P sends for
the first time the byte ADD2, it does not send to the TDA7476 the acknowledge after it has received the byte
BYTE3. In this case, the TDA7476 does not switch from turn-on to permanent diagnostic mode so if it receives
again the byte ADD1 it works as it was the first time that it does the turn-on diagnostic. In order to do repetitive
turn-on diagnostic, the mP has to be programmed as following:
MSB
Step 1: the P sends ADD1
Step 2: the P waits Twait1 seconds
Step 3: the P sends ADD2, receives BYTE1, BYTE2, BYTE3, does not send the acknowlegde after
BYTE3
D7
START
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
D6
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
ADD1
D5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
1
0
1
1
0
1
1
D4
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
1
0
1
1
0
1
1
ACK
D3
X
X
X
X
X
X
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
ACK
D2
X
X
X
X
X
X
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
D1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
1
0
1
1
1
0
LSB
D0
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
1
1
0
1
1
0
1
CH1 short circuit to Vs
CH1 short circuit to GND
CH2 short circuit to Vs
CH2 short circuit to GND
CH3 short circuit to Vs
CH3 short circuit to GND
CH4 short circuit to Vs
CH4 short circuit to GND
AUX1 short circuit to GND
AUX1 open load
AUX2 short circuit to GND
AUX2 open load
CH5 short circuit to Vs
CH5 short circuit to GND
STATUS
TDA7476
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