SLLU332 April   2021 ISOW1044

 

  1.   Trademarks
  2. 1Introduction
  3. 2Overview
  4. 3Pin Configuration of the ISOW1044 Isolated CAN Transceiver with Integrated DC-DC Converter
  5. 4EVM Setup and Operation
  6. 5EVM Schematic
  7. 6PCB Layout and 3D Diagram
  8. 7Bill of Materials

2 Overview

The ISOW1044 device is a galvanically-isolated controller area network (CAN) transceiver with a built-in isolated DC-DC converter that meets the specifications of the ISO11898-2 (2016) standard. This device offers ±58 V DC bus fault protection and ±12 V common-mode voltage range. The device supports CAN FD data rates allowing much faster transfer of payload compared to classic CAN. Both signal and power paths are 5 kVRMS isolated per UL1577 and are qualified for reinforced isolation per VDE, CSA and CQC. The bus pins of these devices can endure up to 8 kV of IEC 61000-4-2 electrostatic discharge (ESD). The low-emissions, isolated DC-DC converter ensures the final system is capable of meeting CISPR 32 radiated emissions Class B limit lines with just two ferrite beads and with simple layout on a two-layer PCB. The device can operate from a single supply voltage of 4.5 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 4.5 V to 5.5 V. This device supports a wide operating ambient temperature range from –40°C to +125°C and are available in 20-pin DFM (SOIC-20 footprint compatible package) offering a minimum of 8-mm creepage and clearance.

The EVM enables a user to evaluate ISOW1044 device thoroughly before incorporating the device into their design. To facilitate the EVM to be powered from various power sources including regulated power supplies, standard DC adaptors and batteries, EVM includes two adjustable output LDOs (LM317M) that are connected to VIO and VDD pins of ISOW1044. This allows the LDO inputs to be connected to a wider range of supply voltages, and the optimum voltage for normal operation of the EVM is between 9 V to 12 V. The EVM also includes an on-board oscillator (LTC6908-1) that can be connected to the input pins (TXD and IN) of ISOW1044 through 0 Ω resistors. The oscillator helps to provide a quick test signal to verify device operation. The EVM can be configured to operate in various power supply voltages and test configurations the details of which are provided in following sections.

The EVM can be used to verify many of ISOW1044 datasheet parameters like input threshold voltages, current consumption and others. Some of the datasheet specifications require a different test setup configuration with necessary terminations than the ISOW1044DFMEVM and hence, they might not be verifiable from the EVM as-is. The example parameters include propagation delay and other timing specifications.