TDA7420 Datasheet, PDF (8/29 Pages) STMicroelectronics – MULTIFUNCTIONAUDIO PROCESSOR

TDA7420
NOTES TO THE CHARACTERISTICS
1 INTERMODULATION SUPPRESSION
α2
=
V_O (signal) (at1KHz)
V_O (spurious) (at1KHZ)
;
f_s
=
(2
x
10KHz)
-
19KHz
α3
=
V_O (signal) (at1KHz)
VO (spurious) (at1KHZ)
;
fs
=
(3
x
13KHz)
-
38KHz
measured with : 91% mono signal; 9% pilot signal; fm=10KHz or 13KHz.
2. TRAFFIC RADIO (V.F.) suppression
α57 (V.W.F.) =
V_O
VO(signal) (at1KHz)
(spurious) (at1KHZ ±23Hz)
measured with : 91% stereo signal; 9% pilot signal; fm=1KHz; 5% subcarrier
(f=57KHz, fm = 23Hz AM, m = 60%)
3. SCA (SUBSIDIARY COMMUNICATIONS AUTHORIZATION)
α67
=
V_O(signal) (at1KHz)
VO (spurious) (at9KHZ)
;
f_s
=
(2
x
38KHz)
-
67KHz
measured with : 81% mono signal; 9% pilot signal; fm=1KHz;
10% SCA - subcarrier (fs = 67KHz, unmodulated).
4. ACI (ADJACENT CHANNEL INTERFERENCE)
α114
=
V_O(signal) (at1KHz)
V_O (spurious) (at4KHZ)
;
f_s
=
110KHz -
(3
x
38KHz)
α190
=
V_O(signal) (at1KHz)
V_O (spurious) (at4KHZ)
;
fs
=
186KHz -
(5
x
38KHz) -
measured with 90% mono signal; 9% pilot signal; fm = 1KHz; 1% spurious signal
(fs = 110KHz or 186KHz, unmodulated).
5: Control range for High Cut Control and Stereo Blend is V_R - 400mV ≤ V_SB, V_HCC ≤V_R
Figure : High Cut Control
Figure : Stereo Blend
fc
(KHz)
D94AU183
SEP
(dB)
D94AU184
40
3
30
2
20
1
10
8/29
0
-500 -400 -300 -200 -100 0 VHCC-VR
0
-400
-300
-200
-100 VSB - VR