HA12167FB Datasheet, PDF (23/73 Pages) Hitachi Semiconductor – Audio Signal Processor for Cassette Deck (Deck 1 Chip)

HA12167FB/HA12169FB
MPX ON/OFF Switch
MPX-OFF mode means that signal from input amp doesn’t go through the MPX filter, but signal goes
through the NR circuit after being attenuated 3 dB by internal resistor. Refer to figure 5. For not cause any
level difference between MPX-ON mode and MPX-OFF mode, it is requested to use MPX-filter which has
definitely 3 dB attenuated. And when applying other usage except figure 5,
take consideration to give bias voltage to NR-IN terminal by resistor or so on because internal of NR-IN
terminal has no bias resistor.
Application as for the Dubbing Cassette Deck
HA12167FB/HA12169FB series has unprocessor signal from recording out terminals during playback
mode. So, it is simply applied for dubbing cassette decks.
2.4 k
IA OUT
MPX
filter
5.6 k
NR IN
Vref
10 mH 220 P
BIAS TRAP
TP
IA
6k
14 k
MPX ON
X1
MPX OFF
1.5 k
NR
processer
3 dB ATT
Figure 5 MPX ON/OFF Switch Block Diagram
Rev.3, Jun. 1997, page 23 of 73