Overview
Description
The ISL31470E, ISL31472E, ISL31475E, and ISL31478E are fault protected, extended common-mode range differential transceivers that exceed the RS-485 and RS-422 standards for balanced communication. The RS-485 bus pins (driver outputs and receiver inputs) are protected against overvoltages up to ±60V. Additionally, these transceivers operate in environments with common-mode voltages up to ±15V (exceeds the RS-485 requirement), making this RS-485 family one of the more robust on the market. Transmitters deliver an exceptional 2. 5V (typical) differential output voltage into the RS-485 specified 54Ω load. This yields better noise immunity than standard RS-485 ICs, or allows up to six 120Ω terminations in star topologies. The receiver (Rx) inputs feature a Full Fail-Safe design that ensures a logic high Rx output if the Rx inputs are floating, shorted, or on a terminated but undriven (idle) bus. The Rx outputs feature high drive levels - typically 15mA at VOL = 1V (to ease the design of opto-coupled isolated interfaces). Half duplex (Rx inputs and Tx outputs multiplexed together) and full duplex pinouts are available. For an RS-485 family with a ±25V extended common-mode range, see the ISL31490E datasheet.
Features
- Fault protected RS-485 bus pins: up to ±60V
- Extended common-mode range: ±15V larger than required for RS-485
- 1/4 unit load for up to 128 devices on the bus
- High transient overvoltage tolerance: ±80V
- Full fail-safe (open, short, terminated) RS-485 receivers
- High Rx IOL for opto-couplers in isolated designs
- Hot plug circuitry - Tx and Rx outputs remain three-state during power-up/power-down
- Choice of RS-485 data rates: 250kbps to 15Mbps
- Low quiescent supply current: 2.3mA
- Ultra low shutdown supply current: 10µA
- Pb-free (RoHS compliant)
Comparison
Applications
- Utility Meters/Automated Meter Reading Systems
- High Node Count Systems
- PROFIBUS™ and Field Bus Networks, and Factory Automation
- Security Camera Networks
- Building Lighting and Environmental Control Systems
- Industrial/Process Control Networks
Design & Development
Models
ECAD Models
Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on products in the Product Options table. If a symbol or model isn't available, it can be requested directly from the website.