1
®
FN6073.4
ISL8488E, ISL8489E, ISL8490E, ISL8491E
±15kV ESD Protected, 5V, Low Power,
High Speed and Slew Rate Limited, Full
Duplex, RS-485/RS-422 Transceivers
The ISL8488E, ISL8489E, ISL8490E, ISL8491E devices are
ESD protected, BiCMOS, 5V powered, single transceivers
that meet both the RS-485 and RS-422 standards for
balanced communication. Each driver output and receiver
input is protected against ±15kV ESD strikes, without
latch-up. Unlike competitive versions, these Intersil devices
are specified for 10% tolerance supplies (4.5V to 5.5V).
These devices are configured for full duplex (separate Rx
input and Tx output pins) applications, so they are ideal for
RS-422 networks requiring high ESD tolerance on the bus
pins. The ISL8488E, ISL8490E are 8 Ld versions without Rx
and Tx output enables. The other two versions include Rx
and Tx output enable pins in a standard 14 Ld pinout.
The ISL8488E, ISL8489E utilize slew rate limited drivers
which reduce EMI, and minimize reflections from improperly
terminated transmission lines, or unterminated stubs in
multidrop and multipoint applications.
Data rates up to 10Mbps are achievable by using the
ISL8490E, ISL8491E, which feature higher slew rates.
The devices present a “single unit load” to the RS-485 bus,
which allows a total of 32 transmitters and receivers on the
network. For “1/8 unit load” versions (256 devices on the
bus), please refer to the ISL4489E, ISL4491E data sheet.
Receiver (Rx) inputs feature a “fail-safe if open” design,
which ensures a logic high Rx output if Rx inputs are floating.
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.
Features
• RS-485 I/O Pin ESD Protection . . . . . . . . . . . . . ±15kV HBM
- Class 3 ESD Level on all Other Pins . . . . . . >7kV HBM
• High Data Rates (ISL8490E, ISL8491E) . . up to 10Mbps
• Slew Rate Limited for Error Free Data Transmission
(ISL8488E, ISL8489E)
• Single Unit Load Allows up to 32 Devices on the Bus
(See ISL4489E, ISL4491E for 256 Devices on Bus)
• Low Quiescent Current:
-120
µA (ISL8488E)
-140
µA (ISL8489E)
-370
µA (ISL8490E, ISL8491E)
• -7V to +12V Common Mode Input Voltage Range
• Three-State Rx and Tx Outputs (Except ISL8488E,
ISL8490E)
• Full Duplex Pinout
• Operates from a Single +5V Supply (10% Tolerance)
• Current Limiting and Thermal Shutdown for Driver
Overload Protection
• Pb-Free Plus Anneal Available (RoHS Compliant)
Applications
• Factory Automation
• Security Networks
• Building Environmental Control Systems
• Industrial/Process Control Networks
• Level Translators (e.g., RS-232 to RS-422)
• RS-232 “Extension Cords”
TABLE 1. SUMMARY OF FEATURES
PART
NUMBER
HALF/FULL
DUPLEX HIGH ESD?
NO. OF DEVICES
ALLOWED ON BUS
DATA RATE
(Mbps)
SLEW-RATE
LIMITED?
RECEIVER/
DRIVER ENABLE?
QUIESCENT
I
CC
(μA)
PIN
COUNT
ISL8488E Full Yes 32 0.25 Yes No 120 8
ISL8489E Full Yes 32 0.25 Yes Yes 140 14
ISL8490E Full Yes 32 10 No No 370 8
ISL8491E Full Yes 32 10 No Yes 370 14
Data Sheet
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
| Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2004, 2007. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
July 26, 2007
