TDA7402_07 Datasheet, PDF (36/71 Pages) STMicroelectronics – Car radio signal processor

Stereo decoder part
TDA7402
5.3.4
ACI (adjacent channel interference)
α 114
=
----^V-----^O----⁽--^s----ⁱ--^g---ⁿ----^a----^l--⁾--⁽---^a----^t--¹---^k---^H-----^z---⁾-----
V_O ( s p u r i o u s ) ( a t 4 kHz )
;f_s
=
110kHz – (3 ⋅ 38kHz)
α 190
=
----^V-----^O----⁽--^s----ⁱ--^g---ⁿ----^a----^l--⁾--⁽---^a----^t--¹---^k---^H-----^z---⁾-----
V_O ( s p u r i o u s ) ( a t 4 kHz )
;f_s
=
186kHz – (5 ⋅ 38kHz)
measured with: 90% mono signal; 9% pilot signal; fm=1kHz; 1% spurious signal
( f_S = 110kHz or 186kHz, unmodulated).
5.4
Noise blanker part
5.4.1
Features:
● AM and FM mode
● internal 2nd order 140kHz high-pass filter for MPX path
● internal rectifier and filters for AM-IF path
● programmable trigger thresholds
● trigger threshold dependent on high frequency noise with programmable gain
● additional circuits for deviation and fieldstrength dependent trigger adjustment
● 4 selectable pulse suppression times for each mode
● programmable noise rectifier charge/discharge current
All parameters measured in FM mode if not otherwise specified.
Table 8. Electrical characteristics
Symbol
Parameter
Test condition
111
110
101
V_TR Trigger threshold ⁽¹⁾
meas.with
V_PEAK=0.9V
100
011
010
001
000
00
Noise controlled
V_{TRNOISE Trigger threshold}
meas.with
01
V_PEAK=1.5V
10
11
Min.
Typ.
30
35
40
45
50
55
60
65
260
220
180
140
Max.
Unit
mV_OP
mV_OP
mV_OP
mV_OP
mV_OP
mV_OP
mV_OP
mV_OP
mV_OP
mV_OP
mV_OP
mV_OP
36/71