JAJS298D DECEMBER   2003  – June 2019 TPS54110

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
  4. 4 改訂履歴
  5. 5 Device Information
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Recommended Operating Conditions
    3. 7.3 Thermal Information
    4. 7.4 Electrical Characteristics
    5. 7.5 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 VBIAS Regulator (VBIAS)
      2. 8.3.2 Voltage Reference
      3. 8.3.3 Oscillator and PWM Ramp
      4. 8.3.4 Error Amplifier
      5. 8.3.5 PWM Control
      6. 8.3.6 Dead-Time Control and MOSFET Drivers
      7. 8.3.7 Overcurrent Protection
      8. 8.3.8 Thermal Shutdown
      9. 8.3.9 Power Good (PWRDG)
    4. 8.4 Undervoltage Lockout (UVLO)
    5. 8.5 Slow-Start/Enable (SS/ENA)
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Typical TPS54110 Application
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Switching Frequency
          2. 9.2.1.2.2 Input Capacitors
          3. 9.2.1.2.3 Output Filter Components
            1. 9.2.1.2.3.1 Inductor Selection
            2. 9.2.1.2.3.2 Capacitor Selection
          4. 9.2.1.2.4 Compensation Components
          5. 9.2.1.2.5 Bias and Bootstrap Capacitors
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Very-Small Form-Factor Application
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 Two-Output Sequenced-Startup Application
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curve
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Layout Considerations For Thermal Performance
    4. 10.4 Grounding and Powerpad Layout
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 デベロッパー・ネットワークの製品に関する免責事項
    2. 11.2 ドキュメントの更新通知を受け取る方法
    3. 11.3 コミュニティ・リソース
    4. 11.4 商標
    5. 11.5 静電気放電に関する注意事項
    6. 11.6 Glossary
  12. 12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

デバイスごとのパッケージ図は、PDF版データシートをご参照ください。

メカニカル・データ（パッケージ｜ピン）
  • PWP|20
サーマルパッド・メカニカル・データ
発注情報

8.5 Slow-Start/Enable (SS/ENA)

The slow-start/enable pin provides two functions; first, the pin acts as an enable (shutdown) control by keeping the device turned off until the voltage exceeds the start threshold voltage of approximately 1.2 V. When SS/ENA exceeds the enable threshold, device start up begins. The reference voltage fed to the error amplifier is linearly ramped up from 0 V to 0.891 V in 3.35 ms. Similarly, the converter output voltage reaches regulation in approximately 3.35 ms. Voltage hysteresis and a 2.5-µs falling edge deglitch circuit reduce the likelihood of triggering the enable due to noise.

The second function of the SS/ENA pin provides an external means of extending the slow-start time with a low-value capacitor connected between SS/ENA and AGND. Adding a capacitor to the SS/ENA pin has two effects on start-up. First, a delay occurs between release of the SS/ENA pin and start up of the output. The delay is proportional to the slow-start capacitor value and lasts until the SS/ENA pin reaches the enable threshold. The start-up delay is approximately:

Equation 2. TPS54110 equation25_lvs500.gif

Second, as the output becomes active, a brief ramp-up at the internal slow-start rate may be observed before the externally set slow-start rate takes control and the output rises at a rate proportional to the slow-start capacitor. The slow-start time set by the capacitor is approximately:

Equation 3. TPS54110 equation26_lvs500.gif

The actual slow-start is likely to be less than the above approximation due to the brief ramp-up at the internal rate.