HA12215F Datasheet, PDF (14/69 Pages) Hitachi Semiconductor – Audio Signal Processor for Cassette Deck(Dolby B-type NR with Recording System)

HA12215F
REC Equalizer
The outlines of REC Equalizing frequency characteristics are shown by figure 9. Those peak level can be
set up by supplying voltage. (0 V to 5 V, GND = 0 V) to pin 10 (GPCAL).
And whole band gain can be set up by supplying voltage (0 V to 5 V, GND = 0 V) to pin 11 (RECCAL).
Both setting up range are ±4.5 dB. In case that you do not need setting up, pin 10, pin 11 should be open
bias.
Note:
Depending on the employed REC/PB head and test tape characteristics, there is a rare case that the
REC-EQ characteristics of this LSI can not be matched to the required characteristics because of
built-in resistors which determined the REC-EQ parameters in this care, please inquire the
responsible agent because of the adjustment of built-in resistor is necessary.
RECCAL
GPCAL
Frequency (Hz)
Figure 9 Frequency Characteristics of REC Equalizer
Bias Switch
HA12215F built-in DC voltage generator for bias oscillator and its bias switches.
External resistor R19, R20, R21 which corresponded with tape positions and bias out voltage are relater
with below.
Vbias =^..
R22
(R19 or R20 or R21) + R22
× (V_CC − V_EE − 0.7) + V_EE
[V]
Bias switch follows to a logic of pin 19 (B / Norm / Crom / Metal).
Note: A current that flows at bias out pin, please use it less than 5 mA.
Rev.5, Oct. 1999, page 14 of 69