ZHCS837F March   2012  – October 2023 TPS7A7300

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 Pin Configurations
  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 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 User-Configurable Output Voltage
      2. 6.3.2 Traditional Adjustable Configuration
      3. 6.3.3 Undervoltage Lockout (UVLO)
      4. 6.3.4 Soft-Start
      5. 6.3.5 Current Limit
      6. 6.3.6 Enable
      7. 6.3.7 Power-Good
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Dropout Operation
      3. 6.4.3 Disabled
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 ANY-OUT Programmable Output Voltage
        2. 7.2.2.2 Traditional Adjustable Output Voltage
        3. 7.2.2.3 Input Capacitor Requirements
        4. 7.2.2.4 Output Capacitor Requirements
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Thermal Considerations
        2. 7.4.1.2 Power Dissipation
        3. 7.4.1.3 Estimating Junction Temperature
      2. 7.4.2 Layout Example
  9. 8 Device And Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 接收文档更新通知
    3. 8.3 支持资源
    4. 8.4 Trademarks
    5. 8.5 静电放电警告
    6. 8.6 术语表
  10. 9 Revision History
  11. 10Mechanical, Packaging, And Orderable Information

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

7.4.1.2 Power Dissipation

Knowing the device power dissipation and proper sizing of the thermal plane that is connected to the tab or pad is critical to avoiding thermal shutdown and providing reliable operation.

Power dissipation of the device depends on input voltage and load conditions and can be calculated using Equation 1:

Equation 1. GUID-A8F1E005-4557-44B1-B953-C3C9291CDFFD-low.gif

Power dissipation can be minimized and greater efficiency can be achieved by using the lowest possible input voltage necessary to achieve the required output voltage regulation.

On the VQFN (RGW ) package, the primary conduction path for heat is through the exposed pad to the PCB. The pad can be connected to ground or be left floating; however, the pad must be attached to an appropriate amount of copper PCB area to make sure the device does not overheat. The maximum junction-to-ambient thermal resistance depends on the maximum ambient temperature, maximum device junction temperature, and power dissipation of the device and can be calculated using Equation 2:

Equation 2. GUID-A8AAD7DB-5E4F-445C-B81F-6011496530AA-low.gif

Knowing the maximum RθJA, the minimum amount of PCB copper area needed for appropriate heat sinking can be estimated using Figure 7-13.

GUID-C8FD852D-A3AD-47FE-A67F-FDA3B974127E-low.gif
The RθJA value at a board size of 9-in2 (that is, 3-in × 3-in) is a JEDEC standard.
Figure 7-13 RθJA vs Board Size

Figure 7-13 shows the variation of RθJA as a function of ground plane copper area in the board. This figure is intended only as a guideline to demonstrate the effects of heat spreading in the ground plane and must not be used to estimate actual thermal performance in real application environments.

Note:

When the device is mounted on an application PCB, ΨJT and ΨJB must be used as explained in the Estimating Junction Temperature section.