ZHCSNA2 October   2021 TPS563212

PRODUCTION DATA  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  4. 4 Revision History
  5. 5 Pin Configuration and 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 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 Advanced Emulated Current Mode Control
      2. 7.3.2 Mode Selection and PG/SS Pin Function Configuration
      3. 7.3.3 Power Good (PG)
      4. 7.3.4 Soft Start and Pre-Biased Soft Start
      5. 7.3.5 Output Discharge Through PG/SS Pin
      6. 7.3.6 Precise Enable and Adjusting Undervoltage Lockout
      7. 7.3.7 Overcurrent Limit and Undervoltage Protection
      8. 7.3.8 Overvoltage Protection
      9. 7.3.9 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
      3. 7.4.3 FCCM Operation
      4. 7.4.4 CCM Operation
      5. 7.4.5 DCM Operation and Eco-mode Operation
      6. 7.4.6 On-Time Extension for Large Duty Cycle Operation
  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 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Output Voltage Resistors Selection
        3. 8.2.2.3 Output Inductor Selection
        4. 8.2.2.4 Output Capacitor Selection
        5. 8.2.2.5 Input Capacitor Selection
        6. 8.2.2.6 Bootstrap Capacitor Selection
        7. 8.2.2.7 Undervoltage Lockout Set Point
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 第三方产品免责声明
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design With WEBENCH® Tools
    2. 11.2 接收文档更新通知
    3. 11.3 支持资源
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 术语表
  12. 12Mechanical, Packaging, and Orderable Information

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机械数据 (封装 | 引脚)
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订购信息

7.3.2 Mode Selection and PG/SS Pin Function Configuration

The device requires a mode resistor to select the operations mode under light load and configure the function of pin 1. Table 7-1 shows the MODE pin settings.

Table 7-1 MODE Pin Settings
MODE RESISTOR RANGERECOMMENDED MODE RESISTOR VALUEOPERATION MODE IN LIGHT LOADFUNCTION OF PG/SS PIN
[0, 12] kΩ0Eco-modePower Good
[30, 50] kΩ47 kΩEco-modeSoft Start
[83, 120] kΩ100 kΩFCCMSoft Start
[180, ∞] kΩFloatFCCMPower Good

Figure 7-1 shows the typical start-up sequence of the device once the enable signal triggers the EN turn-on threshold. After the voltage of VIN crosses the UVLO rising threshold, it takes approximately 110 μs to finish reading and setting of the MODE pin. After this process, the MODE status is latched and does not change until VIN or EN toggles to restart this device. Then, the soft-start function begins to ramp up the reference voltage to the PWM comparator.

GUID-B12919B5-7798-417B-8347-1E4689E48A33-low.gifFigure 7-1 Power-Up Sequence