The LT1785IS8#PBF is a half-duplex and full-duplex Differential Bus Transceiver for RS485 and RS422 applications which features on-chip protection from over-voltage faults on the data transmission lines. Receiver input and driver output pins can withstand voltage faults up to ±60V with respect to ground with no damage to the device. Faults may occur while the transceiver is active, shut down or powered OFF. Data rates to 250kbaud on networks of up to 128 nodes are supported. Controlled slew rates on the driver outputs control EMI emissions and improve data transmission integrity on improperly terminated lines. Driver is specified to operate with inexpensive cables as low as 72R characteristic impedance. This device has fail-safe receiver inputs to guarantee a receiver output high for shorted, open or inactive data lines. On-chip ESD protection eliminates need for external protection device.
Pin-compatible with LTC485 and LTC491
No damage or latch-up to ESD
Controlled slew rates for EMI emissions control
Guaranteed high receiver output state for floating, shorted or inactive inputs
Outputs assume a high impedance when OFF or powered down
(EN)
