Overview

Description

The ISL8487E, ISL81487L, and ISL81487E RS-485/RS-422 devices are ESD protected, fractional unit load (UL), BiCMOS, 5V powered, single transceivers that meet both the RS-485 and RS-422 standards for balanced communication. Each driver output/receiver input is protected against ±15kV ESD strikes without latch-up. Unlike competitive devices, this device family is specified for 10% tolerance supplies (4. 5V to 5. 5V). All devices present a 1/8 unit load to the RS-485 bus, which allows up to 256 transceivers on the network for large node count systems (for example, process automation and remote meter reading systems). In a remote utility meter reading system, individual utility meter readings (in apartments, for example) are routed to a concentrator with an RS-485 network, so the high allowed node count minimizes the number of repeaters required to network all the meters. Data for all meters is then read out from the concentrator from a single access port or a wireless link. Slew rate limited drivers on the ISL8487E and ISL81487L reduce EMI and minimize reflections from improperly terminated transmission lines or unterminated stubs in multidrop and multipoint applications. Data rates up to 250kbps are achievable with these devices. Data rates up to 5Mbps are achievable by using the ISL81487E, which features higher slew rates. The receiver (Rx) inputs feature a “fail-safe if open” design, which ensures a logic high Rx output if Rx inputs are floating. The driver (Tx) outputs are short-circuit protected, even for voltages exceeding the power supply voltage. Additionally, on-chip thermal shutdown circuitry disables the Tx outputs to prevent damage if power dissipation becomes excessive. The half duplex devices multiplex the Rx inputs and Tx outputs to allow transceivers with Rx and Tx disable functions in 8 lead packages.

Features

  • RS-485 I/O pin ESD protection: ±15kV HBM
  • Class 3 ESD level on all other pins: >7kV HBM
  • Fractional unit load allows up to 256 devices on the bus
  • Specified for 10% tolerance supplies
  • High data rate version (ISL81487E): up to 5Mbps
  • Slew rate limited versions for error free data transmission (ISL8487E, ISL81487L): up to 250kbps
  • Low current shutdown mode (except ISL81487E): 0.5μA
  • Low quiescent supply current:
  • ISL8487E, ISL81487L: 145μA (maximum)
  • ISL81487E: 420μA (maximum)
  • -7V to +12V common mode input voltage range
  • Three state Rx and Tx outputs
  • 30ns propagation delays, 5ns skew (ISL81487E)
  • Half duplex pinouts
  • Operate from a single +5V supply (10% tolerance)
  • Current limiting and thermal shutdown for driver overload protection
  • Pin compatible replacements for: MAX487E, (ISL8487E); LTC1487, ADM1487 (ISL81487L); MAX1487E, ST485ER (ISL81487E)
  • Pb-free plus anneal available (RoHS compliant)

Applications

Applications

  • High Node Count Networks
  • Automated Utility Meter Reading Systems
  • Factory Automation
  • Security Networks
  • Building Environmental Control Systems
  • Industrial/Process Control Networks

Documentation

Title Type Date
PDF816 KB
Datasheet
PDF1023 KB
Application Note
PDF207 KB
Application Note
PDF474 KB
Application Note
PDF366 KB
Application Note
PDF178 KB
Application Note
PDF513 KB
Application Note
PDF826 KB
Application Note
PDF443 KB
Application Note
PDF582 KB
Application Note
PDF440 KB
Application Note
PDF338 KB
Application Note
PDF365 KB
Application Note
PDF375 KB
Application Note
PDF4.91 MB日本語
Brochure
PDF2.95 MB
Brochure
PDF156 KB
Other
PDF253 KB
Other
PDF254 KB
Other
PDF106 KB
Product Advisory
PDF266 KB
Product Change Notice
PDF398 KB
Product Change Notice
PDF86 KB
Product Change Notice
PDF108 KB
Product Change Notice
PDF438 KB
Report
PDF188 KB
Technical Brief
PDF300 KB
Technical Brief
PDF920 KB 简体中文
White Paper

Design & Development

Models

Models

Title Type Date
IBS47 KB
Model - IBIS

Support