ZHCSH73B November   2017  – April 2018 TPSM84824

PRODUCTION DATA.  

  1. 特性
  2. 应用
    1.     简化原理图
  3. 说明
    1.     瞬态响应
  4. 修订历史记录
  5. Pin Configuration and Functions
    1.     Pin 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 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics (VIN = 12 V)
    8. 6.8 Typical Characteristics (VIN = 5 V)
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Adjusting the Output Voltage
      2. 7.3.2  Switching Frequency (RT)
      3. 7.3.3  Synchronization (CLK)
      4. 7.3.4  Output On/Off Enable (EN)
      5. 7.3.5  Input Capacitor Selection
      6. 7.3.6  Output Capacitor Selection
      7. 7.3.7  TurboTrans (TT)
        1. 7.3.7.1 Low-ESR Output Capacitors
        2. 7.3.7.2 Transient Response
          1. 7.3.7.2.1 Transient Waveforms (VIN = 12 V)
      8. 7.3.8  Undervoltage Lockout (UVLO)
      9. 7.3.9  Soft Start (SS/TR)
      10. 7.3.10 Sequencing (SS/TR)
      11. 7.3.11 Power Good (PGOOD)
      12. 7.3.12 Safe Start-up into Pre-Biased Outputs
      13. 7.3.13 Overcurrent Protection
      14. 7.3.14 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Shutdown Mode
  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 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Output Voltage Setpoint
        3. 8.2.2.3 Setting the Switching Frequency
        4. 8.2.2.4 Input Capacitors
        5. 8.2.2.5 Output Capacitors
        6. 8.2.2.6 TurboTrans Resistor
        7. 8.2.2.7 Application Waveforms
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
    3. 10.3 EMI
      1. 10.3.1 EMI Plots
    4. 10.4 Package Specifications
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 开发支持
        1. 11.1.2.1 使用 WEBENCH® 工具创建定制设计
    2. 11.2 接收文档更新通知
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 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

Synchronization (CLK)

The TPSM84824 switching frequency can also be synchronized to an external clock from 200 kHz to 1.6 MHz. Not all VIN, VOUT, and IOUT conditions can be set to all of the frequencies in this range due to on-time or off-time limitations. See Table 2 for the allowable operating ranges.

An internal Phase Locked Loop (PLL) has been implemented to allow synchronization and to easily switch from RT mode to CLK mode. To implement the synchronization feature, connect a square wave clock signal to the RT/CLK pin (pin 24) with a duty cycle from 20% to 80%. The clock signal amplitude must transition lower than 0.8 V and higher than 2 V. The start of the switching cycle is synchronized to the falling edge of the RT/CLK pin.

Before the external clock is present the device operates in RT mode and the switching frequency is set by the RT resistor, RRT. Select RRT to set the frequency close to the external synchronization frequency. When the external clock is present, the CLK mode overrides the RT mode. The first time the CLK pin is pulled above the RT/CLK high threshold (2 V), the device switches from the RT mode to the CLK mode and the RT/CLK pin becomes high impedance as the PLL starts to lock onto the frequency of the external clock.

During operation, if the external clock is removed, the internal clock frequency begins to drop. After 10 μs without receiving a clock pulse, the device returns to RT mode. Output undershoot can occur while the switching frequency drops and returns to the frequency set by the RT resistor.