TS-5700
CIRCUIT DESCRIPTION
•
Various Control Circuits by the Digital-to-Ana
log Converter
The circuits whose signal level was varied directly
with a volume control or adjusted with a semi-fixed
volume can be controlled by a microcomputer by us
ing an eight-channel digital-to-analog converter.
The digital-to-analog converter (M62363FP) is a lad
der-type variable attenuator having independent eight
channel inputs. It is used to output an output voltage
by entering a fixed voltage or used as a volume by en
tering the control signal directly. The table below lists
controls in each channel.
CH No. Input pin No.
Output pin No.
1
1
2
2
4
3
3
9
1 0
4
12
1 1
5
13
1 4
6
16
1 5
7
21
22
24
23
VouT8
8bit
Latch
8bit
Latch
VIN1
VouT1
17
Signal name
Control
POC
IFATT1
N C
PRO
TGC
AGC
ALC
CAR
VouT7
8bit
Latch
VouT2
Reference voltage for power control
21.5 to 30MHz IF gain reduction
Not used
Reflected wave protection adjustment
Gain correction between bands and during power control
AGC reference voltage adjustment
ALC reference voltage adjustment
CAR level adjustment
Table 4 Digital-to-analog converter control
V1N2
GND
RESET
VDAref
(8)
VDD
LD
DI
Fig. 13 M62363FP block diagram
V1N3
Output destination
IC 1 6 ALC circuit differential input
IC 1 7 AND gate
I C 1 6 protection input
IC5 operational amplifier
AGC circuit
I C5 operational amplifier
I C2 balan ced modulator
8bit
Latch
8bit
8bit
Latch
Latch
VouT3
VouT4
V1N4
