
1
FN6052.1
ISL83483, ISL83485, ISL83488,
ISL83490, ISL83491
3.3V, Low Power, High Speed or Slew 
Rate Limited, RS-485/RS-422 Transceivers
These Intersil RS-485/RS-422 devices are BiCMOS 3.3V 
powered, single transceivers that meet both the RS-485 and 
RS-422 standards for balanced communication. Unlike 
competitive devices, this Intersil family is specified for 10% 
tolerance supplies (3V to 3.6V).
The ISL83483 and ISL83488 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 
ISL83485, ISL83490, or ISL83491, which feature higher 
slew rates.
Logic inputs (e.g., DI and DE) accept signals in excess of 
5.5V, making them compatible with 5V logic families.
Receiver (Rx) inputs feature a “fail-safe if open” design, 
which ensures a logic high output if Rx inputs are floating. All 
devices present a “single unit load” to the RS-485 bus, which 
allows up to 32 transceivers on the network.
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 ISL83488, ISL83490, ISL83491 are configured for full 
duplex (separate Rx input and Tx output pins) applications. 
The ISL83488 and ISL83490 are offered in space saving 8 
lead packages for applications not requiring Rx and Tx 
output disable functions (e.g., point-to-point and RS-422). 
Half duplex configurations (ISL83483, ISL83485) multiplex 
the Rx inputs and Tx outputs to provide transceivers with Rx 
and Tx disable functions in 8 lead packages.
Features
 Operate from a Single +3.3V Supply (10% Tolerance)
 Interoperable with 5V Logic
 High Data Rates. . . . . . . . . . . . . . . . . . . . .  up to 10Mbps
 Single Unit Load Allows up to 32 Devices on the Bus
 Slew Rate Limited Versions for Error Free Data 
Transmission (ISL83483, ISL83488) . . . . . .up to 250kbps
 Low Current Shutdown Mode (ISL83483, ISL83485, 
ISL83491). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15nA
 -7V to +12V Common Mode Input Voltage Range
 Three State Rx and Tx Outputs (Except ISL83488, 
ISL83490)
 10ns Propagation Delay, 1ns Skew (ISL83485, ISL83490, 
ISL83491)
 Full Duplex and Half Duplex Pinouts
 Current Limiting and Thermal Shutdown for driver 
Overload Protection
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
DATA RATE 
(Mbps)
SLEW-RATE 
LIMITED
RECEIVER/DRIVER 
ENABLE
QUIESCENT I
CC
(mA)
LOW POWER 
SHUTDOWN
PIN COUNT
ISL83483
Half
0.25
Yes
Yes
0.65
Yes
8
ISL83485
Half
10
No
Yes
0.65
Yes
8
ISL83488
Full
0.25
Yes
No
0.65
No
8
ISL83490
Full
10
No
No
0.65
No
8
ISL83491
Full
10
No
Yes
0.65
Yes
14
Data Sheet
September 2003
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
 Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright  Intersil Americas Inc. 2003. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.