ZHCSHN1A August   2017  – February 2018 UCC24612

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      具有高侧 SR 的反激式
      2.      具有低侧 SR 的反激式
  4. 4 修订历史记录
  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 Power Management
      2. 7.3.2 Synchronous Rectifier Control
      3. 7.3.3 Adaptive Blanking Time
        1. 7.3.3.1 Turn-On Blanking Timer (Minimum On Time)
        2. 7.3.3.2 Turn-Off Blanking Timer
        3. 7.3.3.3 SR Turn-on Re-arm
      4. 7.3.4 Gate Voltage Clamping
      5. 7.3.5 Standby Mode
    4. 7.4 Device Functional Modes
      1. 7.4.1 UVLO Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Run Mode
  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 SR MOSFET Selection
        2. 8.2.2.2 Bypass Capacitor Selection
        3. 8.2.2.3 Snubber design
        4. 8.2.2.4 High-Side Operation
      3. 8.2.3 Application Curves
        1. 8.2.3.1 Steady State Testing Low-Side Configuration
        2. 8.2.3.2 Steady State Testing High-Side Configuration
  9. 9 Power Supply Recommendations
  10. 10PCB Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 社区资源
    2. 11.2 商标
    3. 11.3 静电放电警告
    4. 11.4 Glossary
  12. 12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

7.3.3.1 Turn-On Blanking Timer (Minimum On Time)

Right after SR turn-on, for some topologies, such as Flyback, the SR starts to conduct with its maximum current. Due to the parasitic ringing, SR sensed voltage drop may trip the turn-off threshold and prematurely turn off the SR. This is largely caused by the ringing due to the package inductance of the SR MOSFET. The ringing voltage can be managed through appropriate snubbing and use of low package inductance MOSFETs. To further improve the noise immunity, UCC24612-1 blanks the turn-off comparator with a fixed 360-ns (540 ns for UCC24612-2) minimum on-time timer. The SR needs to conduct a minimum of 360 ns (540 ns for UCC24612-2) regardless of its turn-off comparator state. The minimum on-time is short enough to allow the UCC24612 to be used at up to 1 MHz switching frequency (1 MHz for UCC24612-1 and 800kHz for UCC24612-2), while still maintaining good noise immunity. Due to the different applications, the minimum on-time is set up differently for UCC24612-1 and UCC24612-2. For UCC24612-1, the minimum on-time is 360 ns and for UCC24612-2, the minimum on-time is 540 ns.