HA12179F Datasheet, PDF (14/40 Pages) Hitachi Semiconductor – Audio Signal Processer for Car Deck and Cassette Deck(Dolby B-type NR with PB Amp)

HA12179F
The Sensitivity Adjustment of Music Sensor
Adjusting MS AMP. gain by external resistor, the sensitivity of music sensor can set up.
TAI (L)
×1
R28
R26
C28
4700P
MS
VREF
C14 V_CC
R27 0.01µ
R25
R24
330k
+ C13
0.33µ
FFI NOI MA
OUT
MSI MS
DET
D V_CC
I_L
R_L
L·R signal addition circuit
–6dB
+
–
26dB
LPF
25kHz
–
+
MS AMP.
MS OUT
DET
Microcomptuter
D GND
×1
TAI (R)
100k
D GND
Figure 5 Music Sensor Block Diagram
Gv1
Gv
[dB]
Gv2
f₁
f₂
Normal speed
f₃
f₄
FF or REV
10
100
1k
10k 25k 100k
f [Hz]
Figure 6 Frequency Responce
Rev.1, Apr. 1994, page 14 of 40