The MAX491 is a low‑power, half‑duplex RS‑485/RS‑422 transceiver containing one driver and one receiver. It features ±15 kV ESD protection (Human Body Model) and data rates up to 2.5 Mbps, making it ideal for long‑distance, multi‑node industrial communication buses.

| Parameter | Specification | |-----------|---------------| | Protocol | RS‑485 / RS‑422 | | Mode | Half‑duplex | | Data Rate | 2.5 Mbps (max) | | Supply Voltage | 5 V (4.75 V – 5.25 V) | | Quiescent Current | 300 µA (typ) | | Driver Differential Output | ±1.5 V (min) | | Receiver Sensitivity | ±200 mV | | ESD Protection | ±15 kV (HBM) | | Bus Nodes | Up to 32 | | Operating Temp | -40°C ~ +85°C | | Package | 14‑SOIC (ESD) |

- Low power: standby current only 0.5 µA - Thermal shutdown protection - Open‑circuit and short‑circuit fail‑safe receiver - Common‑mode input range: -7 V to +12 V - Bus contention and overload protection

- Industrial automation networks - Building automation - Process control - Instrumentation buses - Security monitoring systems ---