SLUS652E March   2005  – April 2020 UCD8220

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1. 3.1 UCD8220 Typical Simplified Push-Pull Converter Application Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 CLK Input Time-Domain Digital Pulse Train
      2. 7.3.2 Current Sensing and Protection
      3. 7.3.3 Handshaking
      4. 7.3.4 Driver Output
      5. 7.3.5 Source and Sink Capabilities During Miller Plateau
      6. 7.3.6 Drive Current and Power Requirements
      7. 7.3.7 Clearing the Current-Limit Flag (CLF)
    4. 7.4 Device Functional Modes
  8. 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 Selecting the ISET Resistor for Voltage Mode Control
        2. 8.2.2.2 Selecting the ISET Resistor for Voltage Mode Control with Voltage Feed Forward
        3. 8.2.2.3 Selecting the ISET Resistor for Peak Current Mode Control with Internal Slope Compensation
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

封装选项

请参考 PDF 数据表获取器件具体的封装图。

机械数据 (封装 | 引脚)
  • PWP|16
散热焊盘机械数据 (封装 | 引脚)
订购信息

7.3.6 Drive Current and Power Requirements

The UCD8220 device contains drivers that can deliver high current into a MOSFET gate for a period of several hundred nanoseconds. High-peak current is required to turn on a MOSFET. To turn off a MOSFET, the driver is required to sink a similar amount of current to ground. This cycle repeats at the operating frequency of the power device.

For additional information on the current required to drive a power MOSFET and other capacitive-input switching devices, see (5) in the Related Documentation section.

When a driver device is tested with a discrete, capacitive load, calculating the power that is required from the bias supply is fairly simple. Use Equation 1 to calculate the energy that must be transferred from the bias supply to charge the capacitor.

Equation 1. UCD8220 q_1_lus645.gif

where

  • C is the load capacitor
  • V is the bias voltage feeding the driver

An equal amount of energy is transferred to ground when the capacitor is discharged. This transfer of energy results in a power loss which is calculated with Equation 2.

Equation 2. UCD8220 q_2_lus645.gif

where

  • f is the switching frequency

This power is dissipated in the resistive elements of the circuit. Thus, with no external resistor between the driver and gate, this power is dissipated inside the driver. Half of the total power is dissipated when the capacitor is charged, and the other half is dissipated when the capacitor is discharged.

Use Equation 3 to calculate the power loss with the following values: VDD = 12 V, CLOAD = 2.2 nF, and f = 300 kHz.

Equation 3. UCD8220 q_3_lus645.gif

Use Equation 4 to calculate the current with a 12-V supply.

Equation 4. UCD8220 q_4_lus645.gif