3.3V RS485 compatible with 1.8V I/Os and selectable speed 20Mbps or 250kbps


The STR485 is a low power differential line transceiver for data transmission standard RS485 applications in half-duplex mode. Data and enable signals are compatible with 1.8 V or 3.3 V supplies.

Two speeds are selectable through SLR pin: fast data rate up to 20 Mbps or slow data rate for extended cable running to 250 kbps.

Excessive power dissipation caused by bus contention or faults is prevented by thermal shutdown circuit that forces the driver outputs into a high impedance state. The receiver has a fail-safe feature, which guarantees a high output state when the inputs are left open, shorted or idle.

Key Features

  • Half-duplex RS485 transceiver
  • 1.65 V to 3.6 V supply for data and enable signals
  • 3 V to 3.6 V supply for bus supply
  • High speed: up to 20 Mbps data rate
  • Low speed selected by SLR pin : 250 kbps
  • Up to 256 transceivers on the bus
  • Fail safe receiver (bus open, idle and shorted)
  • Thermal shutdown protection
  • Low quiescent current in shutdown mode
  • Extended temperature range : -40 °C to +105 °C
  • Available in industry standard DFN10
  • Bus-pin protection more than:
    • ±4 kV HBM protection
    • ±8 kV IEC61000-4-2 contact discharge
    • ±16 kV IEC61000-4-2 air discharge
    • Compliant IEC61000-4-4 fast transient burst Class B

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