SBASAB3 October   2021 AMC1411-Q1

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  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 Switching Characteristics
    11. 6.11 Timing Diagram
    12. 6.12 Insulation Characteristics Curves
    13. 6.13 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Input
      2. 7.3.2 Isolation Channel Signal Transmission
      3. 7.3.3 Analog Output
    4. 7.4 Device Functional Modes
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Insulation Coordination
        2. 8.2.2.2 Input Filter Design
        3. 8.2.2.3 Differential-to-Single-Ended Output Conversion
      3. 8.2.3 Application Curve
    3. 8.3 What To Do and What Not To Do
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Insulation Coordination

In this example of an OBC, isolation between the high-voltage and low-voltage parts of the system is checked against the requirements of the IEC60664-1 Insulation coordination for equipment within low-voltage systems standard. Isolation must be designed to withstand the rated impulse voltage, temporary overvoltage, and the working voltage. In addition, the physical distance between exposed metal parts on the high- and low-voltage side must meet the minimum creepage and clearance requirements.

Table B.1 of the IEC60664-1 standard defines the impulse voltage for a 1000-V, unearthed system with OVC II as 6000 V. This value is lower than the maximum VIOSM (8000 VPK) rating of the AMC1411-Q1.

Table B.1 of the IEC60664-1 standard also defines the system voltage of a 1000-V, unearthed system as 1000 V. The temporary overvoltage for a system voltage of 1000 V is 2200 V and is derived using the formula (1200 V + system voltage) from IEC60664-1. The value must be doubled for reinforced isolation, resulting in 4400 VRMS or 6250 VPK. This value is lower than the maximum VIOTM (10500 VPK) rating of the AMC1411-Q1.

The working voltage in this example is 1000 VDC and is also lower than VIOWM (2260 VDC) of the AMC1411-Q1.

The minimum clearance for a 6000-V impulse voltage according the IEC60664-1, table F.2, is 8.0 mm for reinforced isolation. For reinforced insulation, the minimum clearance value is taken from the line corresponding to the next higher impulse voltage rating (8000 V), following the guidelines for reinforced isolation. The equipment is designed to operate at altitudes up to 4000 m above sea level and the minimum clearance must be increased to 1.29 × 8 mm = 10.4 mm (rounded up). The factor of 1.29 is taken from table A.2 of the IEC60664-1 standard. The AMC1411-Q1 provides a minimum clearance of 14.7 mm and meets the requirement.

Finally, the minimum creepage distance for a working voltage of 1000 VDC, insulating material group I, pollution degree 2, reinforced isolation is 2 × 5 mm = 10 mm according to IEC60664-1 table F.4. 5 mm is the value for 1000-V basic insulation and is doubled for reinforced isolation. The AMC1411-Q1 provides a minimum creepage of 15.7 mm and provides significant margin against the minimum requirement.