SLLSEY7G June   2017  – February 2025 ISO1211 , ISO1212

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Power Ratings
    6. 5.6  Insulation Specifications
    7. 5.7  Safety-Related Certifications
    8. 5.8  Safety Limiting Values
    9. 5.9  Electrical Characteristics—DC Specification
    10. 5.10 Switching Characteristics—AC Specification
    11. 5.11 Insulation Characteristics Curves
    12. 5.12 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Test Circuits
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Sinking Inputs
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Setting Current Limit and Voltage Thresholds
          2. 8.2.1.2.2 Thermal Considerations
          3. 8.2.1.2.3 Designing for 48V Systems
          4. 8.2.1.2.4 Designing for Input Voltages Greater Than 60V
          5. 8.2.1.2.5 Surge, ESD, and EFT Tests
          6. 8.2.1.2.6 Multiplexing the Interface to the Host Controller
          7. 8.2.1.2.7 Status LEDs
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Sourcing Inputs
      3. 8.2.3 Sourcing and Sinking Inputs (Bidirectional Inputs)
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Related Links
    4. 9.4 Receiving Notification of Documentation Updates
    5. 9.5 Support Resources
    6. 9.6 Trademarks
    7. 9.7 Electrostatic Discharge Caution
    8. 9.8 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.2.1.2.2 Thermal Considerations

Thermal considerations constrain operation at different input current and voltage levels. The power dissipated inside the ISO121x devices is determined by the voltage at the SENSE pin (VSENSE) and the current drawn by the device (I(INx+SENSEx)). The internal power dissipated, when taken with the junction-to-air thermal resistance defined in the Section 5.4 table can be used to determine the junction temperature for a given ambient temperature. The junction temperature must not exceed 150°C.

Figure 8-5 shows the maximum allowed ambient temperature for the ISO1211 device for different current limit and input voltage conditions. The ISO1211 device can be used with a VSENSE voltage up to 60V and an ambient temperature of up to 125°C for an RSENSE value of 562Ω, which corresponds to a typical current limit of 2.25mA. At higher levels of current limit, either the ambient temperature or the maximum value of the VSENSE voltage must be derated. In any design, the voltage drop across the external series resistor, RTHR, reduces the maximum voltage received by the SENSE pin and helps extend the allowable module input voltage and ambient temperature range.

ISO1211 ISO1212 Maximum Ambient Temperature Derating Curve for ISO1211 vs VSENSE
A. This figure also applies to the ISO1212 device if only one of the two channels are expected to be active at a given time.
Figure 8-5 Maximum Ambient Temperature Derating Curve for ISO1211 vs VSENSE

Figure 8-6 shows the maximum allowed ambient temperature for the ISO1212 device for different current limit and input voltage conditions. The ISO1212 device can be used with a VSENSE voltage up to 36V and an ambient temperature of up to 125°C for an RSENSE value of 562Ω, which corresponds to a typical current limit of 2.25mA. At higher current limit levels, either the ambient temperature or the maximum value of the VSENSE voltage must be derated. Operation of the ISO1212 device with an RSENSE value of 200Ω and with both channels active is not recommended beyond a VSENSE voltage of 36V. In any design, the voltage drop across the series resistor, RTHR, reduces the maximum voltage received by the SENSE pin and helps extend the allowable module input voltage and ambient temperature range.

ISO1211 ISO1212 Maximum Ambient Temperature Derating Curve for ISO1212 vs VSENSE
A. This figure only applies if both channels of the ISO1212 device are expected to be on at the same time. If only one channel is expected to be on at a given time, refer to Figure 8-5.
Figure 8-6 Maximum Ambient Temperature Derating Curve for ISO1212 vs VSENSE