DATASHEET ISL8485, ISL8490, ISL8491 FN6046 Rev 10.00 5V, Low Power, High Speed, RS-485/RS-422 Transceivers Oct 18, 2018 The ISL8485, ISL8490, and ISL8491 RS-485/RS-422 Features devices are BiCMOS 5V powered, single transceivers that Specified for 10% tolerance supplies meet both the RS-485 and RS-422 standards for balanced communication. Unlike competitive devices, this family is Class 3 ESD protection (HBM) on all pins: 7kV specified for 10% tolerance supplies (4.5V to 5.5V). High data rates: up to 5Mbps The ISL8485, ISL8490, and ISL8491 feature data rates up to Single unit load allows up to 32 devices on the bus 5Mbps. Low quiescent current: 500A All devices present a single unit load to the RS-485 bus, -7V to +12V common-mode input voltage range which allows up to 32 transceivers on the network. Three state Rx and Tx outputs (except ISL8490) The receiver (Rx) inputs feature a fail-safe if open design, which ensures a logic high Rx output if the Rx inputs are 30ns propagation delays, 5ns skew floating. Full duplex and half duplex pinouts The driver (Tx) outputs are short-circuit protected, even for Operation from a single +5V supply (10% tolerance) voltages exceeding the power supply voltage. Additionally, Current limiting and thermal shutdown for driver overload on-chip thermal shutdown circuitry disables the Tx outputs to protection prevent damage if power dissipation becomes excessive. Pb-free plus anneal (RoHS compliant) The ISL8490 and ISL8491 are configured for full duplex (separate Rx input and Tx output pins) applications. Half Applications duplex configurations (ISL8485) multiplex the Rx inputs and Tx outputs to allow transceivers with Rx and Tx disable Factory automation functions in 8 Ld packages. Security networks Building environmental control systems Related Literature For a full list of related documents, visit our website: Industrial/process control networks ISL8485, ISL8490, and ISL8491 product pages Level translators (for example, RS-232 to RS-422) RS-232 extension cords FN6046 Rev 10.00 Page 1 of 16 Oct 18, 2018ISL8485, ISL8490, ISL8491 Typical Operating Circuits ISL8485 5V 5V 100nF 100nF 8 8 R R PU PU V V CC CC R B 1 RO RO 1 A/Y 6 6 A/Y 2 RE RE 2 R V R T2 FS T1 3 DE DE 3 B/Z 7 7 B/Z 4 DI DI 4 R B GND GND 5 5 ISL8490 5V 5V 100nF 100nF 1 1 V V CC CC A 8 5 Y 2 RO DI 3 R T B 7 6 Z Z 6 7 B 3 DI RO 2 R T Y5 8 A GND GND 4 4 ISL8491 5V 5V 100nF 100nF 13,14 13,14 R R B B R PU R PU V V CC CC A 12 9 Y 2 RO DI 5 R T 3 RE B 11 10 Z DE 4 4 DE Z 10 11 B RE 3 5 DI RO 2 R T Y9 12 A GND GND R R B B 6,7 6,7 To calculate the resistor values, refer to TB509. FN6046 Rev 10.00 Page 2 of 16 Oct 18, 2018