HA12226F Datasheet, PDF (14/84 Pages) Hitachi Semiconductor – Audio Signal Processor for Cassette Deck(Dolby B-type NR with Recording System)

HA12226F/HA12227F
Low-Boost
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).
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
The HA12215F built-in DC voltage generator for bias oscillator and its bias switches.
External resistor R20, R21 which corresponded with tape positions and bias out voltage are relater with below.
Vbias =^..
R22
(R20 or R21) + R22
× (V_CC − 0.7)
[V]
Bias switch follows to a logic of pin 19 (B / Norm / Crom).
Note: A current that flows at bias out pin, please use it less than 5 mA.
Rev.6.00 Jun 15, 2005 page 14 of 83