TDA7402 STMicroelectronics, TDA7402 Datasheet - Page 39

• Manufacturer Part Number: TDA7402
• Description: IC PROCESSOR CAR SIGNAL 44-LQFP
• Manufacturer: STMicroelectronics
• Type: Car Signal Processorr

Specifications of TDA7402

• Applications: Automotive Systems
• Mounting Type: Surface Mount
• Package / Case: 44-LQFP
• Case: QFP
• Dc: 05+
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TDA7402
5.2
5.3
Figure 29. Signals during stereo decoder's Soft Mute
Figure 30. Signal control via Soft Mute pin
InGain + infilter
The InGain stage allows adjustment of the MPX-signal to a magnitude of about 1V
internally, which is the recommended value. The 4
of 80kHz and is used to attenuate spikes and noise, and acts as an anti-aliasing filter for the
following switch capacitor filters.
Demodulator
In the demodulator block, the left and the right channels are separated from the MPX signal.
In this stage the 19kHz pilot tone is cancelled. To reach a high channel separation the
TDA7402 offers an I
for the lowpass behavior of the tuner section. If the tuner's attenuation at 38kHz is in a range
from 7.2% to 31.0%, the TDA7402 needs no external network in front of the MPX-pin. Within
this range, an adjustment to obtain at least 40dB channel separation is possible. The bits for
this adjustment are located together with the fieldstrength adjustment in one byte. This gives
the possibility to perform an optimization step during the production of the car radio, where
SOFTMUTE
PIN
2
C bus programmable roll-off adjustment which is able to compensate
INFLUENCE
SOFTMUTE
IIC-BUS
INFLUENCE
SOFTMUTE
Functional description of stereo decoder
SOFTMUTE
th
INFLUENCE
STDHMUTE
INFLUENCE
PLL-HOLD
order input filter has a corner frequency
MUTED
MP-HOLD
PLL-HOLD
STDHMUTE
D00AU1165
rms
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