TDA7412 Datasheet, PDF (37/56 Pages) STMicroelectronics – CARRADIO SIGNAL PROCESSOR

TDA7412
8.0 DUAL MPX USAGE
8.1 Feature Description
The A679 is able to support a twin tuner concept via the Dual-MPX-Mode. In this configuration the MPX-pin and
the MD2G-pin are acting as MPX1 and MPX2 inputs. The DC-Voltage at the MD2-pin controls whether one or
both MPX-signals are used to decode the stereo FM-signal. It is designed as a window-comparator with the
characteristic shown in Figure 1 (Please note that the thresholds have a hysteresis of 500mV).
In this mode the stereodecoder highohmic-mute mutes both inputs in parallel.
Figure 31.
MPX/
MPX1
100K
MD2G/
MPX2
MD2/
CONTROL
100K
1
40K
40K
1
1
CONTROL
CIRCUITRY
INGAIN
3.5...11dB
step 2.5dB
D00AU1167
8.2 Configuration
The Dual-MPX-Mode can be easily configured by setting bit 3 of subaddress 30 to LOW (see Byte 30 description
and Application Diagram of fig. 33).
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