DATA SHEET
MOS INTEGRATED CIRCUIT
µ
P D 4 7 2 1
RS-232 LINE DRIVER/RECEIVER AT 3.3 V/5 V
The
µ
PD4721 is a high-breakdown voltage silicon gate CMOS line driver/receiver based on the EIA/TIA-232-
E standard. The internal DC/DC converter can switch between multiple voltages, realizing the allowing it to
operate with a single +3.3 V or +5 V power supply. It also provides standby function.
This IC incorporates 2 driver circuits and 2 receiver circuits. An RS-232 interface circuit can be easily
configured by connecting 5 capacitors externally.
FEATURES
• Conforms to EIA/TIA-232-E (former name, RS-232C) standards
• Selectable +3.3 V/+5 V single power supply (selected by V
CHA
pin)
• By setting the standby pin to a low level (standby mode), circuit current can be reduced. At such times,
the driver output is in a high-impedance state.
ORDERING INFORMATION
Part number
Package
20-pin plastic SSOP (300 mil)
µ
PD4721GS-GJG
Document No. S12198EJ2V0DS00 (2nd edition)
(Previous No. IC-3279)
Date Published January 1997 N
Printed in Japan
©
1993
µ
PD4721
BLOCK DIAGRAM/PIN CONFIGURATION (Top View)
+10 V
C
3
+
+
1
V
DD
C
4
+ 20
+
C
4
2
+3.3 V
or
+5 V
C
1
C
1
+
GND 19
+
C
2
C
4
– 18
3
V
CC
4
C
1
–
C
5
+
V
SS
17
–10 V
5
C
5
+
6
16 STBY
C
5
–
Note 4
300
Ω
300
Ω
15 V
CHA
D
IN1
7
14 D
OUT1
D
IN2
8
13 D
OUT2
R
OUT1
9
5.5 kΩ
12 R
IN1
R
OUT2
10
5.5 kΩ
11 R
IN2
Note 1.
V
DD
and V
SS
are output pins stepped up internally. These pins should not be loaded directly.
2.
Capacitors C
1
to C
5
with a breakdown voltage of 20 V or higher are recommended. And it is
recommended to insert the capacitor that is 0.1
µ
F to 1
µ
F between V
CC
and GND.
3.
If V
CHA
is kept low level (in 5 V mode), capacitor C
5
is not necessary.
4.
The pull-up resistors at driver input are active resistors.
2
µ
PD4721
Truth Table
Driver
STBY
L
H
H
D
IN
D
OUT
Z
H
L
Remarks
Standby mode (DC/DC converter is stopped)
Space level output
Mark level output
×
L
H
Receiver
STBY
L
H
H
R
IN
R
OUT
H
H
L
Remarks
Standby mode (DC/DC converter is stopped)
Mark level input
Space level input
×
L
H
3 V
↔
5 V switching
V
CHA
L
H
Note 5
Operating mode
5 V mode (double step-up)
3 V mode (3 times step-up)
H: high-level, L: low-level, Z: high-impedance,
×:
H or L
Note 5.
When switching V
CHA
, standby mode must be selected (STBY = L).
3
µ
PD4721
ABSOLUTE MAXIMUM RATINGS
(T
A
= 25
°C)
Parameter
Supply Voltage (V
CHA
= L)
Supply Voltage (V
CHA
= H)
Driver Input Voltage
Receiver Input Voltage
Control Input Voltage (STBY, V
CHA
)
Driver Output Voltage
Receiver Output Voltage
Input Current (D
IN
, STBY, V
CHA
)
Operating Ambient Temperature
Storage Temperature
Total Power Dissipation
Symbol
V
CC
V
CC
D
IN
R
IN
V
IN
D
OUT
R
OUT
I
IN
T
A
T
stg
P
T
Ratings
–0.5 to +7.0
–0.5 to +4.5
–0.5 to V
CC
+0.5
–30.0 to +30.0
–0.5 to V
CC
+0.5
–25.0 to +25.0
Note 6
–0.5 to V
CC
+0.5
±20.0
–40 to +85
–55 to +150
0.5
Unit
V
V
V
V
V
V
V
mA
°C
°C
W
Note 6.
Pulse width = 1 ms, duty = 10 % MAX.
RECOMMENDED OPERATING CONDITIONS
Parameter
Supply Voltage (V
CHA
= L, 5 V mode)
Supply Voltage (V
CHA
= H, 3 V mode)
High-Level Input Voltage (D
IN
)
Low-Level Input Voltage (D
IN
)
High-Level Input Voltage (STBY, V
CHA
)
Low-Level Input Voltage (STBY, V
CHA
)
Receiver Input Voltage
Operating Ambient Temperature
Capacitance of External Capacitor
Symbol
V
CC
V
CC
V
IH
V
IL
V
IH
V
IL
R
IN
T
A
Note 7
MIN.
4.5
3.0
2.0
0
2.4
0
–30
–40
0.33
TYP.
5.0
3.3
MAX.
5.5
3.6
V
CC
0.8
V
CC
0.6
+30
+85
4.7
Unit
V
V
V
V
V
V
V
°C
µ
F
Note 7.
In low temperature (below 0 ˚C), the capacitance of electrolytic capacitor becomes lower. Therefore,
set higher values when using in low temperature.
Concerning the wiring length between the capacitor and the IC, the shorter the better.
Capacitors with good frequency characteristics such as tantalum capacitors, laminated ceramic
capacitors, and aluminum electrolytic capacitors for switching power supply are recommended for the
external capacitors.
4
µ
PD4721
ELECTRICAL SPECIFICATIONS (TOTAL)
(Unless otherwise specified, T
A
= –40 to +85
°C,
C
1
to C
5
= 1
µ
F)
Parameter
Symbol
Conditions
V
CC
= +3.3 V, No load, R
IN
pin OPEN,
STBY = H
V
CC
= +5.0 V, No load, R
IN
pin OPEN,
STBY = H
V
CC
= +3.3 V, R
L
= 3 kΩ (D
OUT
), D
IN
= GND,
R
IN
, R
OUT
pin OPEN, STBY = H
V
CC
= +5.0 V,R
L
= 3 kΩ (D
OUT
), D
IN
= GND,
R
IN
, R
OUT
pin OPEN, STBY = H
V
CC
= +3.3 V, No load, D
IN
and R
IN
pins are OPEN, STBY = L, T
A
= 25
°C
V
CC
= +3.3 V, No load, D
IN
and R
IN
pins are OPEN, STBY = L
Circuit Current at Standby
I
CC3
V
CC
= +5.0 V, No load, D
IN
and R
IN
pins are OPEN, STBY = L, T
A
= 25
°C
V
CC
= +5.0 V, No load, D
IN
and R
IN
pins are OPEN, STBY = L
High-Level Input Voltage
Low-Level Input Voltage
High-Level Input Current
Low-Level Input Current
V
IH
V
IL
I
IH
I
IL
V
CC
= +3.0 to +5.5 V, STBY, V
CHA
pin
V
CC
= +3.0 to +5.5 V, STBY, V
CHA
pin
V
CC
= +5.5 V, V
I
= +5.5 V, STBY, V
CHA
pin
V
CC
= +5.5 V, V
I
= 0 V, STBY, V
CHA
pin
Driver input and receiver input
V
CC
= +3.3 V, for GND, f = 1 MHz
Driver input and receiver input
V
CC
= +5.0 V, for GND, f = 1 MHz
STBY — V
CHA
Time
V
CHA
— STBY Time
STBY — V
CC
Time
V
CC
— STBY Time
t
SCH
t
CHS
t
SC
t
CS
V
CC
= +3.0 to +5.5 V, STBY
↓ →
V
CHA
,
V
CC
= +3.0 to +5.5 V, V
CHA
→
STBY
↑,
V
CC
= +3.0 to +5.5 V, STBY
↓ →
V
CC
,
V
CC
= +3.0 to +5.5 V, V
CC
→
STBY
↑,
Note 8
Note 8
MIN.
TYP.
6.5
4.5
19
14
1
5
2
10
MAX.
13
9
24
18
3
Unit
mA
mA
mA
mA
Circuit Current
I
CC1
Circuit Current
I
CC2
µ
A
µ
A
5
µ
A
µ
A
V
2.4
0.6
1
–1
10
V
µ
A
µ
A
pF
Input Capacitance
C
IN
10
1
1
1
1
pF
µ
s
µ
s
µ
s
µ
s
Note 8
Note 8
*
The TYP. values are for reference at T
A
= 25
°C.
Note 8.
Measuring point
5V
STBY
0.6 V
0V
t
SCH
3.3 V
2.4 V
V
CHA
0V
5V
V
CC
3.3 V
4.5 V
3.6 V
4.5 V
3.6 V
t
SC
0.6 V
t
CS
t
SC
2.4 V
0.6 V
t
CS
t
CHS
t
SCH
t
CHS
0.6 V
0.6 V
0.6 V
3.3 V
5
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