LT1785AIN8

Product Summary

The LT1785AIN8 is a half-duplex and full-duplex differential bus transceiver for RS485 and RS422 applications which feature on-chip protection from overvoltage 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. Drivers are specified to operate with inexpensive cables as low as 72W characteristic impedance. The LT1785AIN8 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 devices. The LT1785AIN8 is available in 8-lead DIP and SO packages. The applications of the device include Industrial Control Data Networks, CAN Bus Applications and HVAC Controls.

Parametrics

LT1785AIN8 absolute Maximum Ratings: (1)Supply Voltage (VCC): 18V; (2)Receiver Enable Input Voltage: - 0.3V to 6V; (3)Driver Enable Input Voltage: - 0.3V to 6V; (4)Driver Input Voltage: -0.3V to 18V; (5)Receiver Input Voltage: - 60V to 60V; (6)Driver Output Voltage: - 60V to 60V; (7)Receiver Output Voltage: - 0.3V to (VCC + 6V); (8)Operating Temperature Range: -40℃ to 85℃; (9)Storage Temperature Range: -65℃ to 150℃; (10)Lead Temperature (Soldering, 10 sec): 300℃.

Features

LT1785AIN8 features: (1)Protected from Overvoltage Line Faults to ±60V; (2)Pin Compatible with LTC485 and LTC491; (3)High Input Impedance Supports Up to 128 Nodes; (4)No Damage or Latchup to ESD; (5)Controlled Slew Rates for EMI Emissions Control; (6)Guaranteed High Receiver Output State for Floating, Shorted or Inactive Inputs; (7)Outputs Assume a High Impedance When Off or Powered Down; (8)Drives Low Cost, Low Impedance Cables; (9)Short-Circuit Protection on All Outputs; (10)Thermal Shutdown Protection.

Diagrams