HA12203NT Datasheet, PDF (11/97 Pages) Hitachi Semiconductor – Audio Signal Processor for Cassette Deck(Dolby B-type NR with Recording System)

Input Block Diagram and Level Diagram
HA12203NT/HA12204NT
The each level shown above is typical value _MS
when offering PBOUT level to PBOUT pin.
REF
300mVrms
PASS
REC
PB _PB/REC,
PB=5.7dB/5.7dB
PBOUT
580mVrms
FLAT
AIN
(120µ)
300mVrms
21.3dB
PB
0dB
BIN
25.9mVrms
70µs
REC
300mVrms
DOLBY
B-NR
RECOUT
300mVrms
R3
12k
R4
15k
PASS _PB/REC,
PASS=0dB/17dB
42.4mVrms
C2
RIN ^{HA12204NT is not built-in Dolby noise reduction system.}
0.0047µF
Figure 2 Input Block Diagram
PB Equalizer
By switching logical input level of 13 pin (for Ain) and 15 pin (for Bin), you can equalize corresponding to
tape position at play back mode.
With the capacity C2 capacitance that we showed for figure 2 70 µs by the way figure seem to 3 they are
decided.
Gv
t1
t2
t1 = C2 • (12k + 15k)
t2 = C2 • 15k
f
Figure 3 Frequency Characteristic of PB Equalizer
Rev.3, Jun. 1999, page 11 of 97