ZHCSH39B November   2017  – September 2019 ISOW7821

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     简化原理图
  4. 4 修订历史记录
  5. 5 说明 （续）
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Power Ratings
    6. 7.6  Insulation Specifications
    7. 7.7  Safety-Related Certifications
    8. 7.8  Safety Limiting Values
    9. 7.9  Electrical Characteristics—5-V Input, 5-V Output
    10. 7.10 Supply Current Characteristics—5-V Input, 5-V Output
    11. 7.11 Electrical Characteristics—5-V Input, 3.3-V Output
    12. 7.12 Supply Current Characteristics—5-V Input, 3.3-V Output
    13. 7.13 Electrical Characteristics—3.3-V Input, 3.3-V Output
    14. 7.14 Supply Current Characteristics—3.3-V Input, 3.3-V Output
    15. 7.15 Switching Characteristics—5-V Input, 5-V Output
    16. 7.16 Switching Characteristics—5-V Input, 3.3-V Output
    17. 7.17 Switching Characteristics—3.3-V Input, 3.3-V Output
    18. 7.18 Insulation Characteristics Curves
    19. 7.19 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Electromagnetic Compatibility (EMC) Considerations
      2. 9.3.2 Power-Up and Power-Down Behavior
      3. 9.3.3 Current Limit, Thermal Overload Protection
    4. 9.4 Device Functional Modes
      1. 9.4.1 Device I/O Schematics
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curve
        1. 10.2.3.1 Insulation Lifetime
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 PCB Material
    2. 12.2 Layout Example
  13. 13器件和文档支持
    1. 13.1 器件支持
      1. 13.1.1 开发支持
    2. 13.2 文档支持
      1. 13.2.1 相关文档
    3. 13.3 接收文档更新通知
    4. 13.4 社区资源
    5. 13.5 商标
    6. 13.6 静电放电警告
    7. 13.7 Glossary
  14. 14机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

10.2.2 Detailed Design Procedure

The ISOW7821 device only requires external bypass capacitors to operate. These low-ESR ceramic bypass capacitors must be placed as close to the chip pads as possible.

ISOW7821 isow782x-typical-circuit-hookup.gif
Optional 100 µF capacitor can be added between VCC and GND1; refer to Power Supply Recommendations.
Figure 31. Typical Circuit Hook-Up

The VCC power-supply input provides power to isolated data channels and to the isolated DC-DC converter. Use Equation 1 to calculate the total power budget on the primary side.

Equation 1. ICC = (VISO × IISO) / (η × VCC) + Iinpx

where

  • ICC is the total current required by the primary supply.
  • VISO is the isolated supply voltage.
  • IISO is the external load on the isolated supply voltage.
  • η is the efficiency.
  • VCC is the supply voltage.
  • Iinpx is the total current drawn for the isolated data channels and power converter when data channels are toggling at a specific data rate. This data is shown in the Electrical Characteristics—5-V Input, 5-V Output table.