SLLSF86D May   2018  – August 2026 ISOW1412 , ISOW1432

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Power Ratings
    6. 6.6  Insulation Specifications
    7. 6.7  Safety-Related Certifications
    8. 6.8  Safety Limiting Values
    9. 6.9  Electrical Characteristics
    10. 6.10 Supply Current Characteristics at VISOOUT = 3.3 V
    11. 6.11 Supply Current Characteristics at  VISOOUT = 5 V
    12. 6.12 Switching Characteristics at VISOOUT = 3.3 V
    13. 6.13 Switching Characteristics at VISOOUT = 5 V
    14. 6.14 Insulation Characteristics Curves
    15. 6.15 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Power Isolation
    3. 8.3 Signal Isolation
    4. 8.4 RS-485
    5. 8.5 Functional Block Diagram
    6. 8.6 Feature Description
      1. 8.6.1 Power-Up and Power-Down Behavior
      2. 8.6.2 Protection Features
      3. 8.6.3 Failsafe Receiver
      4. 8.6.4 Glitch-Free Power Up and Power Down
    7. 8.7 Device Functional Modes
    8. 8.8 Device I/O Schematics
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Data Rate, Bus Length and Bus Loading
        2. 9.2.2.2 Stub Length
      3. 9.2.3 Insulation Lifetime
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

3 Description

The ISOW14x2 devices are galvanically-isolated RS-485/RS-422 transceivers with a built-in isolated DC-DC converter, that eliminates the need for a separate isolated power supply in space constrained isolated designs. The low-emissions, isolated DC-DC converter meets CISPR 32 radiated emissions Class B standard with just two ferrite beads on a simple two-layer PCB. Additional 20mA output current can be used to power other circuits on the board. An integrated 2Mbps GPIO channel helps remove any additional digital isolator or optocoupler for diagnostics, LED indication or supply monitoring.

Two options of data rates are provided: ISOW1412 is optimized for maximum 500kbps and ISOW1432 is designed for maximum 12Mbps data rate. These devices do not require any external components other than bypass capacitors to realize an isolated RS-485 port, designed for long distance communications. Isolation breaks the ground loop between the communicating nodes, allowing for a much larger common mode voltage range. Both signal and power paths are 5kVRMS isolated per UL1577 and are qualified for reinforced and basic isolation per VDE, TUV, CSA and CQC.

The ISOW14x2 can operate from a single supply voltage of 3V to 5.5V by connecting VIO and VDD together on PCB. If lower logic levels are required, 1.71V to 5.5V logic supply (VIO) can be separated and independent from the power converter supply (VDD) of 3V to 5.5V. These devices support 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 8mm creepage and clearance.

ISOW1412 ISOW1432 Simplified Schematic Simplified Schematic