UM491EESE全双工RS422收发器

Product Description

The UM491 is ±15kV electrostatic discharge (ESD)-protected, high-speed transceivers for RS-422 communication that contain one driver and one receiver. The device features fail-safe circuitry, which guarantees a logic-high receiver output when the receiver inputs are open or shorted. This means that the receiver output will be a logic high if all transmitters on a terminated bus are disabled (high impedance). The UM491 offers higher driver output slew-rate limits, allowing transmit speeds up to 2.5Mbps. The device features enhanced ESD protection. All transmitter outputs and receiver inputs are protected to ±15kV using the Human Body Model.

These transceivers typically draw 375μA of supply current when unloaded, or when fully loaded with the drivers disabled.

The device has a 1/8-unit-load receiver input impedance that allows up to 256 transceivers on the bus. The UM491 is intended for full-duplex communications.

Features

- ESD Protection for RS-422 I/O Pins

  ±15kV, Human Body Model

- True Fail-Safe Receiver While Maintaining EIA/TIA-422 Compatibility

- Enhanced Slew-Rate Limiting Facilitates

- Error-Free Data Transmission

- 1nA Low-Current Shutdown Mode

- Allow Up to 256 Transceivers on the Bus

Applications

- RS-422 Communications

- Level Translators

- Transceivers for EMI-Sensitive Applications

- Industrial-Control Local Area Networks