ISO35T - Isolated 3.3V Full-Duplex RS-485 Transceiver with Integrated Transformer Driver

The ISO35T is an isolated differential line transceiver with integrated oscillator outputs that provide the primary voltage for an isolation transformer. The device is a full-duplex differential line transceiver for RS-485 and RS-422 applications that can easily be configured for half-duplex operation by connecting pin 11 to pin 14, and pin 12 to pin 13.

These devices are ideal for long transmission lines since the ground loop is broken to allow for a much larger common-mode voltage range. The symmetrical isolation barrier of the device is tested to provide 4242V_PK of isolation per VDE for 60s between the bus-line transceiver and the logic-level interface.

Any cabled I/O can be subjected to electrical noise transients from various sources. These noise transients can cause damage to the transceiver and/or near-by sensitive circuitry if they are of sufficient magnitude and duration. The ISO35T can significantly reduce the risk of data corruption and damage to expensive control circuits.

The ISO35T is specified for use from –40°C to 85°C.

• Designed for RS-485 and RS-422 Applications
• Signaling Rates up to 1 Mbps
• 1/8 Unit Load – up to 256 Nodes on a Bus
• Thermal Shutdown Protection
• Typical Efficiency > 60% (I_LOAD = 100 mA)
  - See SLUU470
• Low-Driver Bus Capacitance 16 pF (Typical)
• Fail-Safe Receiver for Bus Open, Short, Idle
• Logic Inputs are 5-V Tolerant
• 50-kV/µs Typical Transient Immunity
• Bus-Pin ESD Protection
  • 16-kV HBM Between Bus-Pins and GND2
  • 6-kV HBM Between Bus-Pins and GND1
• Safety and Regulatory Approvals
  • 4242 V_PK Basic Insulation per DIN V VDE V
    0884-10 and DIN EN 61010-1
  • 2500 V_RMS Isolation for 1 minute per UL 1577
  • CSA Component Acceptance Notice 5A, IEC
    60950-1 and IEC 61010-1 Standards