SP331 Datasheet, PDF (1/13 Pages) Sipex Corporation – Programmable RS-232/RS-485 Transceiver

SP331
Programmable Dual RS-232/RS-485 Transceiver
• +5V Only Operation
• Software Programmable RS-232 or RS-485
Selection
• Four RS-232 Transceivers in RS-232 Mode
• Two RS-485 Full-Duplex Transceivers in
RS-485 Mode
• Two RS-232 Transceivers and One RS-485
Transceiver in Dual Mode
• Self-Testing Loopback Mode
• Full Driver Tri-State (Hi-Z) Control
• Ideal for RS-232 to RS-485 conversion
TI4 1
SEL_B 2
TX4 3
TX3 4
VCC 5
TX1 6
TX2 7
GND 8
C1+ 9
V+ (VDD) 10
C2+ 11
C1– 12
C2– 13
V– (VSS) 14
28 TI3
27 TI2
26 TI1
25 SEL_C
24 SEL_A
23 SEL_D
22 RX4
21 RX3
20 RX2
19 RX1
18 RI4
17 RI3
16 RI2
15 RI1
DESCRIPTION
The SP331 is a programmable RS-232 and/or RS-485 transceiver IC. The SP331 contains
four drivers and four receivers when selected in RS-232 mode; and two drivers and two
receivers when selected in RS-485 mode. The SP331 also contains a dual mode which has
two RS-232 drivers/receivers plus one differential RS-485 driver/receiver.
The RS-232 transceivers can typically operate at 230kbps while adhering to the RS-232 speci-
fications. The RS-485 transceivers can operate up to 10Mbps while adhering to the RS-485
specifications. The SP331 includes a self-test loopback mode where the driver outputs are
internally configured to the receiver inputs. This allows for easy diagnostic serial port testing
without using an external loopback plug. The RS-232 and RS-485 drivers can be disabled
(High-Z output) by controlling a set of four select pins.
TYPICAL APPLICATIONS CIRCUIT
0.1µF
0.1µF
+5V
+5V
TTL/CMOS
TTL/CMOS
TTL/CMOS
TTL/CMOS
TTL/CMOS
TTL/CMOS
TTL/CMOS
TTL/CMOS
+5V
5
9 _C1+
12 _C1-
11 _C2+
VCC
SP331
10
V+
14
V-
0.1µF
13
C2-
24 _{SEL A}
2 _{SEL B}
Vcc
400KΩ
26 TI1
T1
27 _{TI2 Vcc}
400KΩ
28 TI3
T3
1 _TI4
19 RX1
R1
20 _RX2
0.1µF
23
SEL D
0V
TX2 7
TX1 6
TX4 3
TX3 4
RI2 16
15KΩ
RI1 15
15KΩ
RS-485
RS-485
RS-485
RS-485
RS-485
RS-485
21 RX3
R3
22 _RX4
8 _GND
RI4 18
15KΩ
RI3 17
15KΩ
25
SEL C
RS-485
RS-485
0V
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com

SP331_100_012610