SLLU324A February   2019  – April 2021 ISOW1412


  1.   Trademarks
  2. 1Introduction
  3. 2Functional Block Diagram and Device Pin Configuration of ISOW1412
    1. 2.1 Functional Block Diagram and Device Pin Configuration
  4. 3EVM Schematic
  5. 4EVM 3D Diagram and PCB Layout
  6. 5Bill of Materials
  7. 6EVM Setup and Operation
  8. 7Support Resources


ISOW1412 is a galvanically-isolated differential line transceiver with a built-in isolated DC-DC converter for TIA/EIA RS-485 and RS-422 applications. Both signal and power paths are isolated per UL1577 and are qualified for reinforced isolation per VDE, CSA and CQC. These devices do not require any external components other than bypass capacitors to realize an isolated RS-485 port. The low-emissions, isolated DC/DC converter ensures the final system is capable of meeting CISPR 32 radiated emissions limit lines with just two ferrite beads.

The device is ideal for long distance communications. Isolation breaks the ground loop between the communicating nodes, allowing for a much larger common-mode voltage range. It supports a maximum datarate of 500 kbps. It can operate from a single supply voltage of 3 V to 5.5 V by connecting VIO and VDD together on PCB. If lower logic levels are required, these devices support 1.71 V to 5.5 V logic supply (VIO) that can be independent from the power converter supply (VDD) of 3 V to 5.5 V. These devices support a wide operating ambient temperature range from –40°C to 105°C and are available in 20-pin DFM (SOIC footprint compatible package) offering a minimum of 8 mm creepage and clearance.

ISOW1412DFMEVM can be used to evaluate different system parameters of the devices. Test signals and sequences can be applied to the device and different performance characteristics can be observed such as propagation delay, power consumption, and different bus and driver conditions. Users can evaluate these parameters in their own lab environment.

The EVM has footprints named DNI for additional components that are not needed to test the standard functionality. Add components to these footprints for evaluation and to get specific system requirements. Refer to this users guide for the basic functionality that can be assessed with the EVM.