The MAX3070E–MAX3079E 3.3V, ±15kV ESD-protected, RS-485/RS-422 transceivers feature one driver and one receiver. These devices include fail-safe circuitry, guaranteeing a logic-high receiver output when receiver inputs are open or shorted. The receiver outputs a logic high if all transmitters on a terminated bus are disabled (high impedance). The MAX3070E–MAX3079E include a hot-swap capability to eliminate false transitions on the bus during power-up or hot insertion.
The MAX3070E/MAX3071E/MAX3072E feature reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission up to 250kbps. The MAX3073E/MAX3074E/MAX3075E also feature slew-rate-limited drivers but allow transmit speeds up to 500kbps. The MAX3076E/MAX3077E/MAX3078E driver slew rates are not limited, making transmit speeds up to 16Mbps possible. The MAX3079E slew rate is pin selectable for 250kbps, 500kbps, and 16Mbps.
The MAX3072E/MAX3075E/MAX3078E are intended for half-duplex communications, and the MAX3070E/MAX3071E/MAX3073E/MAX3074E/MAX3076E/MAX3077E are intended for full-duplex communications. The MAX3079E is selectable for half-duplex or full-duplex operation. It also features independently programmable receiver and transmitter output phase through separate pins.
The MAX3070E-MAX3079E transceivers draw 800µA of supply current when unloaded or when fully loaded with the drivers disabled. All devices have a 1/8-unit load receiver input impedance, allowing up to 256 transceivers on the bus.