HA12215F Datasheet, PDF (13/69 Pages) Hitachi Semiconductor – Audio Signal Processor for Cassette Deck(Dolby B-type NR with Recording System)

HA12215F
Music Sensor Output (MSOUT)
As for internal circuit of music sensor block, music sensor output pin is connected to the collector of
NPN type directly, output level will be “high” when sensing no signal. And output level will be “low”
when sensing signal.
Connection with microcomputer, it is requested to use external pull up resistor (R_L = 10 kΩ to 22 kΩ)
Note: Supply voltage of MSOUT pin must be less than V_CC voltage.
The Tolerances of External Components
For Dolby NR precision securing, please use external components shown at figure 7. If leak-current are a
few electrolytic-capacitor, it can be applicable to C5 and C23.
V_{EE C23}
0.1µ
±10%
42
DET (L)
HA12215F
Low-Boost
DET (R) BIAS1
1
2
C5
0.1µ
±10%
R5
33k
V_EE ^±2%
Figure 7 Tolerance of External Components
24.6dB
EQIN
4.8k
REC EQ
4.8k
EQOUT
BOOST
+_C9(C19)
0.47µ
Figure 8 Example of Low Boost Circuit
External components shown figure 8 gives frequency response to take 6 dB boost. And cut off frequency
can request it, by C9 (C19).
Rev.5, Oct. 1999, page 13 of 69