Onkyo TX-SR702 - Page 60

TX-SR702/E
IC BLOCK DIAGRAMS AND DESCRIPTIONS
uPD4721GS (RS-232C Driver/ Receiver)
1
2
3
4
5
6
7
8
9
10
5.5k ohm
5.5k ohm
300 ohm
300 ohm
V DD
C 1
V CC
C 1
C S
C S
D IN1
D IN2
R OUT1
R OUT2
C 4
GND
C 4
V SS
STBY
V CHA
D OUT1
D OUT2
R IN1
R IN2
20
19
18
17
16
15
14
13
12
11
Block diagram
Truth table
STBY
L
H
H
DIN
X
L
H
DOUT
Z
H
L
Standby mode (DC/DC converter is stopped)
Space level output
Mark level output
Remarks
Driver
Receiver
STBY
L
H
H
R
IN
X
L
H
R
OUT
H
H
L
Standby mode (DC/DC converter is stopped)
Space level input
Space lev
el input
Remarks
3 V/5 V switching
V
CHA
L
H
Oper
ating mode
5 V mode (double step-up)
3 V mode (3 times step-up)