HA12203NT Datasheet, PDF (16/97 Pages) Hitachi Semiconductor – Audio Signal Processor for Cassette Deck(Dolby B-type NR with Recording System)

HA12203NT/HA12204NT
Bias Switch
This series built-in DC voltage generator for bias oscillator and its bias switches.
External resistor R15, R16, R17 Which corresponded with tape positions and bias out voltage are relater
with below.
Vbias =..
R14
(R15 or R16 or R17) + R14
× (V_CC − V_EE − 0.7) + V_EE [V]
Bias switch follows to a logic of 15 pin (B / Norm / Crom / Metal).
Note: A current that flows at bias out pin, please use it less than 5 mA.
BIAS (N)
R15
P25
BIAS (C)
R16
P24
BIAS (M)
R17
P23
Vbias
R14
V_EE
Figure 11 External Components of Bias Block
Rev.3, Jun. 1999, page 16 of 97