ISL4485E

5V, Half Duplex, 20Mbps, ±15kV ESD Protected, RS-485/RS-422 Transceiver

Product Status: Mass Production

OVERVIEW

The Intersil ISL4485E is a high speed, BiCMOS 5V powered, single transceiver that meets 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 Intersil device is specified for 10% tolerance supplies (4.5V to 5.5V).

The excellent differential output voltage coupled with high drive-current output stages allow 20Mbps operation over twisted pair networks up to 450 feet in length. The 25kΩ receiver input resistance presents a "single unit load" to the RS-485 bus, allowing up to 32 transceivers on the network. 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.

The half duplex configuration multiplexes the Rx inputs and Tx outputs to allow transceivers with Rx and Tx disable functions in 8 lead packages.

KEY FEATURES

  • Pb-Free Available (RoHS Compliant)
  • High Data Rates up to 20Mbps
  • RS-485 I/O Pin ESD Protection ±15kV HBM
  • Class 3 ESD Level on all Other Pins >7kV HBM
  • Operates from a Single +5V Supply (10% Tolerance)
  • 1 Unit Load Allows up to 32 Devices on the Bus
  • Low Quiescent Current 700µA
  • -7V to +12V Common Mode Input Voltage Range
  • Three State Rx and Tx Outputs
  • 30ns Propagation Delays, 2ns Skew
  • Current Limiting and Thermal Shutdown for driver Overload Protection

BLOCK DIAGRAM

 Block Diagram

PARAMETRICS

Parameters
ISL4485E
Basic Information
Production Status
Mass Production
Key Feature
High Speed
# of Tx
1
# of Rx
1
Devices Allowed on Bus
32
Half/Full Duplex
Half
High ESD Protection
Yes
Hot Plug
No
Data Rate
20 Mbps
Supply Voltage Vcc (Min) (V)
4.5
Supply Voltage Vcc (Max) (V)
5.5
Slew Rate Limited
No
Tx/Rx Enable
Yes
IS Enabled/Disabled
550/340 µA
SHDN ICC
N/A µA
VL Pin
No
Qualification Level
Standard
Supply Voltage Vcc Range (V)
4.5 to 5.5
Can Sample
YES
Temperature Range
-40 to +85

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