SLLSFO4D December   2022  – August 2025 ISOM8710 , ISOM8711

PRODMIX  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  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—DC 
    10. 6.10 Switching Characteristics, ISOM8710
    11. 6.11 Switching Characteristics, ISOM8711
    12. 6.12 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
  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 Sizing RIN
        2. 9.2.2.2 Driving the Input with a Buffer
        3. 9.2.2.3 Calculating RL for ISOM8711
      3. 9.2.3 Application Curves
      4. 9.2.4 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
    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

9.2.2.2 Driving the Input with a Buffer

The input of ISOM871x can be driven by an inverting buffer or non-inverting buffer to change the truth table of the ISOM871x or provide sufficient input forward current to drive the device. Using a buffer is optional. If a buffer is used, the equation for RIN remains the same as shown above.

Sizing RIN based on the output voltage of the buffer, VBUF, and the desired forward input current, IF, Equation 1 becomes:

Equation 3. RIN = VBUF - VF MAXIF

For example, using a buffer with a 5V output, and a desired IF of 5mA, RIN is calculated as:

Equation 4. RIN = 5 V - 1.8 V5 mA =640 Ω