TD3085

The TD308X series is a transceiver designed for RS485 and RS422 communication systems, supporting data transmission and reception at rates up to 1Mbps. This series provides a half-duplex RS485 interface with driver enable and receiver enable control pins. The receiver features 1/4 unit load input impedance, allowing up to 128 loads to be connected on the bus. The series integrates one driver and one receiver, employing a reduced slew rate design to minimize EMI and reflections caused by improper cable termination. The receiver incorporates input filtering to improve noise rejection for slowly rising and falling differential signals, at the cost of a 25% increase in propagation delay. No fail-safe circuitry is included; when the differential input signal is between -200mV and +200mV, the receiver output state is indeterminate. When the bus is idle, a pull-up resistor must be added to port A to ensure the receiver output remains high. The driver output features foldback current limiting and thermal shutdown protection to prevent damage from overcurrent and overheating.

Applications

• Low-power RS485 and RS422 receivers
• Electric, water, and gas meters
• Level translation
• Access control and security systems
• EMI-resistant transceivers
• Industrial control LAN

Key features

• Three-state output
• Half-duplex communication
• A/B terminal short-circuit protection
• SOP8 package