LT1785IN8#PBF, RS-422/RS-485 Interface IC 60V Fault Protected RS485/RS422 Trans

LT1785 is fault protected half-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. Driver is specified to operate with inexpensive cables as low as 72ohm characteristic impedance. Typical applications are industrial control data networks, CAN bus applications, HVAC controls.

• Pin compatible with LTC485 and LTC491
• No damage or latchup to ESD, outputs assume a high impedance when off or powered down
• IEC-1000-4-2 level 4 is ±15kV air discharge, IEC-1000-4-2 level 2 is ±4kV contact discharge
• Drives low cost, low impedance cables, short-circuit protection on all outputs
• Differential driver output voltage (unloaded) is 4.1V at IO=0, TA=25°C, VCC=5V
• Driver common mode output voltage is 2.5V typical R=27ohm or R=50 ohm, TA=25°C, VCC=5V
• Input voltage is 2V (high), 0.8V (low) at DI, DE, active-low RE, TA=25°C, VCC=5
• Input current is 5µA at DI, DE, active-low RE, TA=25°C, VCC=5
• 8-lead PDIP package, -40°C to 85°C temperature rating
• Thermal shutdown protection