HA12237F Datasheet, PDF (6/33 Pages) Renesas Technology Corp – Audio Signal Processor for Cassette Deck

HA12237F
Block Diagram
As this IC is built-in REC return switch, the configuration system can be simple system using a few external component
and the REC/PB head.
About these logics, please look at the Parallel Data Format.
8.2k
B head
A head
RECOUT(L)
21
2.2µ
35
34
BIN(L)
AIN(L)
32
31
24
23
REC-EQ
120k
To ALC
Return SW
B
120k
A
+
− _330k
93/120
180
(High/Norm)
42k
12k
30
29
To 27
0.1µ
5.1k 5.1k
28
EQOUT(L)
0.01µ
Figure 2 Block Diagram (Lch)
Unit R: Ω
C: F
PB Equalizer
The gain establishment of PB-EQ considers PB output level {(internal Line Amp. + PB Amp.) = 580 mVrms} like
figure 3 at the target.
After replace RA and RB with a half-fix volume, adjust level.
REC-EQ adjust the gain in front of input to this IC.
The level digram of 1 kHz is shown figure 3.
Please set “RA + RB ≥ 10 kΩ”
0.6mV ^PB-EQ
41.2dB
Line Amp.
25.7dB
68mV 30mV
580mV
RA
RB
Figure 3 PB System Level Diagram (1 kHz)
Rev.1.00 Jun 15, 2005 page 6 of 32