SNOSDF8 December   2024 LM74680

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 Electrical Characteristics
    6. 5.6 Switching Characteristics
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Input and Output Voltage
      2. 7.3.2 Charge Pump
      3. 7.3.3 Gate Drivers
      4. 7.3.4 Enable
    4. 7.4 Device Functional Modes
      1. 7.4.1 Conduction Mode
        1. 7.4.1.1 Regulated Conduction Mode
        2. 7.4.1.2 Full Conduction Mode
      2. 7.4.2 Reverse Current Protection Mode
  9. 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 Design Considerations
        2. 8.2.2.2 MOSFET Selection
        3. 8.2.2.3 Output Capacitance
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Transient Protection
    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 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ

8.2.2.3 Output Capacitance

A minimum ceramic capacitor of 0.1μF is recommended to be placed across the OUTP and GND pins as close to the LM74680 as possible for decoupling. Additional output capacitance COUT may be required to ensure that the rectified output voltage remains within the recommended operating range of the LM74680 and also to meet the output voltage ripple requirements of downstream circuitry depending on the system's tolerance.

The additional capacitance required between OUTP and GND is based on the downstream power demands and the allowable voltage ripple. COUT in the hundreds to thousands of microfarads is common. A good starting point is selecting COUT such that:

Equation 1. C O U T   ≥   I L O A D   /   V R I P P L E   ×   2   ×   F r e q

Where,

  • ILOAD is the average output load current
  • VRIPPLE is the maximum tolerable output ripple voltage
  • Freq is the frequency of the input AC source

For example, in a 50Hz, 24V AC application where the load current is 1A and the tolerable ripple is 1V, choose COUT ≥ 1A/(10V × 2 × 50Hz) = 1mF.