DATASHEET
ISL4485E FN6049
Rev 3.00
April 21, 2005 В±15kV ESD Protected, 20Mbps, 5V, Low Power, RS-485/RS-422 Transceiver
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 В±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 25kпЃ—
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 …