JAJS448D March   2010  – October 2018 TPS54260

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      概略回路図
      2.      効率と負荷電流との関係
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Fixed Frequency PWM Control
      2. 8.3.2  Slope Compensation Output Current
      3. 8.3.3  Pulse-Skip Eco-Mode
      4. 8.3.4  Low-Dropout Operation and Bootstrap Voltage (BOOT)
      5. 8.3.5  Error Amplifier
      6. 8.3.6  Voltage Reference
      7. 8.3.7  Adjusting the Output Voltage
      8. 8.3.8  Enable and Adjusting Undervoltage Lockout
      9. 8.3.9  Slow-Start / Tracking Pin (SS/TR)
      10. 8.3.10 Overload Recovery Circuit
      11. 8.3.11 Sequencing
      12. 8.3.12 Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
      13. 8.3.13 Overcurrent Protection and Frequency Shift
      14. 8.3.14 Selecting the Switching Frequency
      15. 8.3.15 How to Interface to RT/CLK Pin
      16. 8.3.16 Powergood (PWRGD Pin)
      17. 8.3.17 Overvoltage Transient Protection
      18. 8.3.18 Thermal Shutdown
      19. 8.3.19 Small Signal Model for Loop Response
      20. 8.3.20 Simple Small Signal Model for Peak Current Mode Control
      21. 8.3.21 Small Signal Model for Frequency Compensation
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operation Near Minimum Input Voltage
      2. 8.4.2 Operation With Enable Control
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 3.3-V Output Application
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1  Custom Design With WEBENCH® Tools
          2. 9.2.1.2.2  Selecting the Switching Frequency
          3. 9.2.1.2.3  Output Inductor Selection (LO)
          4. 9.2.1.2.4  Output Capacitor
          5. 9.2.1.2.5  Catch Diode
          6. 9.2.1.2.6  Input Capacitor
          7. 9.2.1.2.7  Slow-Start Capacitor
          8. 9.2.1.2.8  Bootstrap Capacitor Selection
          9. 9.2.1.2.9  Undervoltage Lock Out Set Point
          10. 9.2.1.2.10 Output Voltage and Feedback Resistors Selection
          11. 9.2.1.2.11 Compensation
          12. 9.2.1.2.12 Discontinuous Mode and Eco-Mode Boundary
          13. 9.2.1.2.13 Power Dissipation Estimate
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Inverting Power Supply
      3. 9.2.3 Split-Rail Power Supply
      4. 9.2.4 12-V to 3.8-V GSM Power Supply
      5. 9.2.5 24-V to 4.2-V GSM Power Supply
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 デバイス・サポート
      1. 12.1.1 デベロッパー・ネットワークの製品に関する免責事項
      2. 12.1.2 開発サポート
        1. 12.1.2.1 WEBENCH®ツールによるカスタム設計
    2. 12.2 ドキュメントの更新通知を受け取る方法
    3. 12.3 コミュニティ・リソース
    4. 12.4 商標
    5. 12.5 静電気放電に関する注意事項
    6. 12.6 Glossary
  13. 13メカニカル、パッケージ、および注文情報

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.2.1.2.13 Power Dissipation Estimate

The following formulas show how to estimate the IC power dissipation under continuous conduction mode (CCM) operation. These equations should not be used if the device is working in discontinuous conduction mode (DCM).

The power dissipation of the IC includes conduction loss (Pcon), switching loss (PSW), gate drive loss (PGD) and supply current (Pq).

Equation 49. TPS54260 eq56_lvs795.gif
Equation 50. TPS54260 eq57_lvs795.gif
Equation 51. TPS54260 eq58_lvs795.gif
Equation 52. TPS54260 eq59_lvs795.gif

where

  • IOUT is the output current (A)
  • RDS(on) is the on-resistance of the high-side MOSFET (Ω)
  • VOUT is the output voltage (V)
  • VIN is the input voltage (V)
  • fsw is the switching frequency (Hz)

So

Equation 53. TPS54260 eq60_lvs795.gif

For given TA,

Equation 54. TPS54260 eq61_lvs795.gif

For given TJMAX = 150°C

Equation 55. TPS54260 eq62_lvs795.gif

where

  • Ptot is the total device power dissipation (W)
  • TA is the ambient temperature (°C)
  • TJ is the junction temperature (°C)
  • Rth is the thermal resistance of the package (°C/W)
  • TJMAX is maximum junction temperature (°C)
  • TAMAX is maximum ambient temperature (°C).

There will be additional power losses in the regulator circuit due to the inductor ac and dc losses, the catch diode and trace resistance that will impact the overall efficiency of the regulator.