TDA7406T Datasheet, PDF (23/49 Pages) STMicroelectronics – CAR RADIO SIGNAL PROCESSOR

TDA7406T
Note 4. ACI (Adjacent Channel Interference)
α114 = -_V----^V_o---₍-^o-_s--⁽--_ps----_ui-^g---_r-ⁿ-_i--_o-^a---_u-^l--⁾_s--⁽--₎-^a-₍---_at--¹-_t--_4k----^Hk----_H-^z---⁾-_z---₎ ;ƒ_s = 110kH z – (3 ⋅ 38 kHz )
α190 = -_V----^V_o---₍-^o-_s--⁽--_ps----_ui-^g---_r-ⁿ-_i--_o-^a---_u-^l--⁾_s--⁽--₎-^a-₍---_at--¹-_t--_4k----^Hk----_H-^z---⁾-_z---₎ ;ƒ_s = 186kH z – (5 ⋅ 38 kHz )
measured with: 90% mono signal; 9% pilot signal; fm=1kHz; 1% spurious signal (f_s = 110kHz or 186kHz, un-
modulated).
3.2 Dual MPX Usage
3.2.1 Feature Description
The TDA7406T is able to support a twin tuner concept via the Dual-MPX-Mode. The DC-Voltage at the CMPX-
pin controls whether one or both MPX-signals are used to decode the stereo FM-signal. Therefor two window-
comparators with a characteristic as shown in Figure 17 are implemented (Please note that the thresholds have
a hysteresis of 500mV).
In this mode the stereodecoder high impedance-mute mutes both inputs in parallel.
Figure 17. Block diagram Dual MPX
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