SP331 SP33 Programmable Dual RS-232/RS-485 Transceiver +5V Only Operation 1 28 TI4 TI3 Software Programmable RS-232 or RS-485 SEL B 2 27 TI2 Selection 3 26 TX4 TI1 Four RS-232 Transceivers in RS-232 Mode 4 25 TX3 SEL C Two RS-485 Full-Duplex Transceivers in VCC 5 24 SEL A 6 23 TX1 SEL D RS-485 Mode 7 22 TX2 RX4 Two RS-232 Transceivers and One RS-485 8 21 GND RX3 Transceiver in Dual Mode C1+ 9 20 RX2 Self-Testing Loopback Mode 10 19 V+ (VDD) RX1 11 18 Full Driver Tri-State (Hi-Z) Control C2+ RI4 C1 12 17 RI3 Ideal for RS-232 to RS-485 conversion 13 16 C2 RI2 14 15 V (VSS) RI1 DESCRIPTION The SP33 is a programmable RS-232 and/or RS-485 transceiver IC. The SP33 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 SP33 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 +5V 5 9 C1+ VCC 0.1F 10 0.1F 12 V+ C1- 14 11 SP331 V- C2+ 0.1F 13 0.1F C2- 24 23 +5V SEL A SEL D 0V 2 SEL B +5V Vcc TX2 7 400K RS-485 26 TI1 TTL/CMOS T1 6 TX1 27 RS-485 TI2 TTL/CMOS Vcc TX4 3 400K RS-485 TI3 28 TTL/CMOS T3 4 TX3 RS-485 1 TI4 TTL/CMOS RI2 16 RS-485 RX1 19 TTL/CMOS R1 15K RI1 15 RS-485 20 RX2 15K TTL/CMOS RI4 18 RS-485 21 RX3 15K R3 TTL/CMOS RI3 17 RS-485 22 15K RX4 TTL/CMOS 25 0V 8 SEL C GND Exar Corporation 48720 Kato Road, Fremont CA, 94538 50-668-70 7 www .exar.com SP33 00 0 26 0 ABSOLUTE MAXIMUM RATINgS These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. Storage Temperature.......................-65C to +150C V .......................................................................+7V CC Power Dissipation Input Voltages 28-pin WSOIC................................... 000mW Logic............................-0.5V to (Vcc+0.5V) Package Derating: Drivers.........................-0.5V to (Vcc+0.5V) 28-pin WSOIC Receivers......................+/-30V 100mA ................................................40 C/W JA Driver Outputs..................................................+/- 5V Maximum Data Rate..........................8Mbps (Note 1) SPECIFICATIONS Limits are specified at T = 25C and V = +5.0V unless otherwise noted. A CC PARAMETER MIN. TYP. MAX. UNITS CONDITIONS LOgIC INPUTS V 0.8 Volts IL V 2.0 Volts IH LOgIC OUTPUTS V 0.4 Volts I = -3.2mA OL OUT V 2.4 Volts I = .0mA OH OUT RS-232 DRIVER DC Characteristics HIGH Level Output +5.0 + 5.0 Volts R = 3k, V = 0.8V L IN LOW Level Output - 5.0 -5.0 Volts R = 3k, V = 2.0V L IN Open Circuit Voltage - 5 +5 Volts Short Circuit Current +/- 00 mA V = 0V OUT Power Off Impedance 300 V = 0V, V = +/-2.0V CC OUT AC Characteristics Slew Rate 30 V/s R = 3k, C = 50pF V = +5.0V, L L CC T 25C A Transistion Time .5 s R = 3k, C = 2500pF between L L +/-3V, T +25C A Maximum Data Rate 20 235 kbps R = 3k, C = 2500pF L L Propagation Delay t 2 8 s Measured from 1.5V of V to 50% PHL IN of V R = 3k OUT L Propagation Delay t 2 8 s PLH RS-232 RECEIVER DC Characteristics HIGH Threshold .7 3.0 Volts LOW Threshold 0.8 .2 Volts Receiver Open Circuit Bias +2.0 Volts Input Impedance 3 5 7 k V = + 5V to -5V IN Exar Corporation 48720 Kato Road, Fremont CA, 94538 50-668-70 7 www.exar.com SP33 00 0 26 0 2