ST3085A 250kbps ±15kV ESD High-ESD-Protected Fail-Safe RS-485 Transceiver

Overview

The ST3085A is a high-ESD-protected half-duplex RS-485 transceiver integrating one driver and one receiver, operating from a single +3.3V or +5V supply. Its I/O pins provide ±15kV ESD protection per IEC 61000-4-2 contact discharge, making it well suited to electrostatically demanding industrial environments. True fail-safe circuitry guarantees a logic-high receiver output when the receiver inputs are open or shorted, even if every transmitter on a terminated bus is disabled. The reduced-slew-rate driver minimizes EMI and reflections caused by improperly terminated cables, enabling error-free data transmission up to 250kbps. With a 1/8 unit-load receiver input impedance, up to 256 transceivers can share a single bus for half-duplex communication. Offered in an SOP-8 package over a -40~+85℃ operating temperature range, the ST3085A delivers a highly reliable RS-485 interface for industrial control LANs, energy meter networks and lighting systems.

Features

• Single +3.3V or +5V supply operation
• True fail-safe receiver: logic-high output on open/shorted inputs
• Max data rate: 250kbps
• Reduced-slew-rate driver minimizes EMI and cable reflections
• 1/8 unit-load input impedance allows up to 256 transceivers on the bus
• I/O pin ESD protection: ±15kV IEC 61000-4-2 contact discharge
• 350µA typical supply current, less than 10µA in shutdown mode
• SOP-8 package

Typical Applications

• RS-485 communications
• Level translators
• Transceivers for EMI-sensitive applications
• Industrial control local area networks
• Energy meter networks
• Lighting systems