HA12167FB Datasheet, PDF (29/73 Pages) Hitachi Semiconductor – Audio Signal Processor for Cassette Deck (Deck 1 Chip)

HA12167FB/HA12169FB
Equalizer Characteristics Control Using a Bias DAC
When only one of the bias DAC channels is used, any one of the six parameters (FM, fQ, f/Q, GH, GL, and
GP) that set the equalizer’s chara cteristics can controlled by the unused bias DAC.
The figure below gives one example.
R _ADJ
37
36
35
34
33
6 bit
DAC
32
31
30
6 bit
DAC
EQ-
controller
29
28
FM
27
26 ^fQ
f/Q
25
GH
24
GL
23
GP
22
21 ^HM
16 17 18 19 20
NN NC NM HN HC
BIAS ADJ (C)
BIAS ADJ (M)
BIAS ADJ (N)
GND
BIAS CONT
DAC OUT
V_CC
R’_GP
R _GP = R’_GP //
63 R_ADJ
2n
n: DAC step
Figure 11 Bias DAC Control of the GP Parameter
Rev.3, Jun. 1997, page 29 of 73