STMicroelectronics STR485LV: 3.3 V RS485 Transceiver – Flexible, Low‑Voltage, High‑Performance

The STMicroelectronics STR485LV is a 3.3‑V RS485 transceiver that gives designers full control over data rate through a simple pin, enabling either 20 Mbps for high‑speed, short‑range links or 250 kbps for extended distances up to 4000 ft (1.2 km) depending on cable performance. Its low‑power interface accepts logic as low as 1.8 V, eliminating the need for level shifters and simplifying inventory management for applications ranging from telecom infrastructure to low‑voltage microcontroller communication.

Designed for seamless integration, the STR485LV operates on a 1.65‑3.6 V supply and maintains an internal driver‑output resistance above 96 Ω even at 105 °C. This robustness allows up to 256 transceivers to share the same bus in accordance with the RS485 specification, while the direct 1.8‑3.3 V logic compatibility removes extra components from the board.

Safety and reliability are built‑in: thermal shutdown protects against bus contention or over‑current, and a receiver failsafe mode guards against idle, shorted, or floating inputs. The bus pins withstand over ±8 kV contact discharge and ±16 kV air discharge without latch‑up, exceeding IEC 61000‑4‑2, and resist IEC 61000‑4‑4 fast‑transient bursts (class‑B). Encased in a compact 3 mm × 3 mm DFN10 package with flow‑through logic‑to‑bus pinning, the STR485LV cuts board space and BOM while delivering industry‑grade performance.