MAX3081

The MAX3080MAX3089 high-speed transceivers for RS-485/RS-422 communication contain one driver and one receiver. These devices feature 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 MAX3080/MAX3081/MAX3082 feature reduced slew-rate drivers that minimize EMI and reduce reflec- tions caused by improperly terminated cables, allowing error-free data transmission up to 115kbps. The MAX3083/MAX3084/MAX3085 offer higher driver out- put slew-rate limits, allowing transmit speeds up to 500kbps. TheMAX3086/MAX3087/MAX3088's driver slew rates are not limited, making transmit speeds up to 10Mbps possible. The MAX3089's slew rate is selectable between 115kbps, 500kbps, and 10Mbps by driving a selector pin with a single three-state driver.

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

All devices have a 1/8-unit-load receiver input imped- ance that allows up to 256 transceivers on the bus. The MAX3082/MAX3085/MAX3088 are intended for half- duplex communications, while the MAX3080/MAX3081/ MAX3083/MAX3084/MAX3086/MAX3087 are intended for full-duplex communications. The MAX3089 is selec- table between half-duplex and full-duplex operation. It also features independently programmable receiver and transmitter output phase via separate pins.