TDA7402 STMicroelectronics, TDA7402 Datasheet - Page 41

• 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
5.8
5.9
Stereo blend control
The stereo blend control block converts the internal LEVEL voltage (LEVELSB) into an
demodulator compatible analog signal which is used to control the channel separation
between 0dB and the maximum separation. Internally this control range has a fixed upper
limit which is the internal reference voltage REF5V. The lower limit can be programmed
between 20 and 70% of REF5V in 3.3% steps (see
To adjust the external LEVEL voltage to the internal range two values must be defined: the
LEVEL gain L
external level signal has to be amplified that internally it becomes equal to REF5V. The
second point (e.g. 10dB channel sep.) is then adjusted with the VSBL voltage.
Figure 31. Internal stereo blend characteristics
The gain can be programmed through 4 bits in the "Stereo decoder adjustment" byte. All
necessary internal reference voltages like REF5V are derived from a bandgap circuit.
Therefore they have a temperature co-efficient near zero.
Figure 32. Relation between internal and external LEVEL voltages for setup of
Highcut control
The highcut control set-up is similar to the stereo blend control set up: the starting point
VHCH can be set with 2 bits to be 42, 50, 58 or 66% of REF5V whereas the range can be
set to be 17, 22, 28 or 33% of VHCH (see
VOLTAGES
INTERNAL
REF 5V
VSBL
stereo blend
VMO
G
SETUP OF VST
and VSBL (see
VST
LEVEL
FIELDSTRENGHT VOLTAGE
Figure
t
LEVEL INTERN
32). At the point of full channel separation the
Figure
VSBL
VOLTAGES
INTERNAL
Functional description of stereo decoder
REF 5V
33).
70%
20%
D00AU1168
Figure 31
VMO
SETUP OF VMO
and 32).
VST
LEVEL INTERN
FIELDSTRENGHT VOLTAGE
t
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