Description

The MAX1481/MAX1484/MAX1485/MAX1486 providesoftware-selectable, half-/full-duplex, low-power, slew-rate-limited, and high-speed (12Mbps) RS-485/RS-422operation in a 10-pin µMAX® package—the smallest10-pin package available.The software-selectable, half-/full-duplex MAX1485/MAX1486 make obsolete the normally larger and moreexpensive solutions required for selectable half-/full-duplexRS-485/RS-422 operation: 1) a 14-pin, full-duplextransceiver configured via jumpers betweenreceiver and transmitter lines, or 2) two 8-pin, half-duplextransceivers, which require an additional inverterlogic gate for software selectability.The MAX1481/MAX1484 are functionally equivalent tothe industry-standard MAX491 and 75180, and aredesigned for space-constrained, full-duplex RS-422applications.All parts contain one driver and one receiver and featurea 1/8-unit-load receiver input impedance, allowingup to 256 transceivers on the bus. The MAX1481/MAX1485 feature reduced-slew-rate drivers that minimizeEMI and reduce reflections caused by improperlyterminated cables, allowing error-free data transmissionup to 250kbps. The MAX1484/MAX1486 driver slewrates are not limited, allowing them to transmit up to12Mbps.The MAX1481/MAX1484/MAX1485/MAX1486 draw only300µA of supply current. The MAX1481 has a low-powershutdown mode that reduces supply current to only0.1µA. All devices operate from a single 5V supply.Drivers are output short-circuit current limited and areprotected against excessive power dissipation bythermal-shutdown circuitry that places the driver outputsinto a high-impedance state. The receiver input has a fail-safefeature that guarantees a logic-high output if theinput is open circuit.ApplicationsBattery-Powered ApplicationsHandheld EquipmentIndustrial Control Local Area NetworksLevel TranslatorsLow-Power RS-422/RS-485 CommunicationsTransceivers for EMI-Sensitive Applications