JAJSGD4C July   2015  – October 2018 LM5160-Q1

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      代表的な同期整流降圧アプリケーション回路
      2.      代表的なFly-Buckアプリケーション回路
  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 Switching Characteristics
    7. 7.7 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  Control Circuit
      2. 8.3.2  VCC Regulator
      3. 8.3.3  Regulation Comparator
      4. 8.3.4  Soft Start
      5. 8.3.5  Error Amplifier
      6. 8.3.6  On-Time Generator
      7. 8.3.7  Current Limit
      8. 8.3.8  N-Channel Buck Switch and Driver
      9. 8.3.9  Synchronous Rectifier
      10. 8.3.10 Enable / Undervoltage Lockout (EN/UVLO)
      11. 8.3.11 Thermal Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Forced Pulse Width Modulation (FPWM) Mode
      2. 8.4.2 Undervoltage Detector
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Ripple Configuration
    2. 9.2 Typical Applications
      1. 9.2.1 LM5160-Q1 Synchronous Buck (10-V to 60-V Input, 5-V Output, 1.5-A Load)
        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  Feedback Resistor Divider - RFB1, RFB2
          3. 9.2.1.2.3  Switching Frequency - RON
          4. 9.2.1.2.4  Inductor - L
          5. 9.2.1.2.5  Output Capacitor - COUT
          6. 9.2.1.2.6  Series Ripple Resistor - RESR
          7. 9.2.1.2.7  VCC and Bootstrap Capacitors - CVCC, CBST
          8. 9.2.1.2.8  Input Capacitor - CIN
          9. 9.2.1.2.9  Soft-Start Capacitor - CSS
          10. 9.2.1.2.10 EN/UVLO Resistors - RUV1, RUV2
        3. 9.2.1.3 Application Curves
      2. 9.2.2 LM5160-Q1 Isolated Fly-Buck (18-V to 32-V Input, 12-V, 4.5-W Isolated Output)
        1. 9.2.2.1 LM5160-Q1 Fly-Buck Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 Selection of VOUT1 and Turns Ratio
          2. 9.2.2.2.2 Secondary Rectifier Diode
          3. 9.2.2.2.3 External Ripple Circuit
          4. 9.2.2.2.4 Output Capacitor - COUT2
        3. 9.2.2.3 Application Curves
    3. 9.3 Do's and Don'ts
  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 ドキュメントのサポート
      1. 12.2.1 関連資料
    3. 12.3 ドキュメントの更新通知を受け取る方法
    4. 12.4 コミュニティ・リソース
    5. 12.5 商標
    6. 12.6 静電気放電に関する注意事項
    7. 12.7 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

9.2.2.2.1 Selection of VOUT1 and Turns Ratio

The primary-side output voltage of a Fly-Buck converter must be no more than one half of the minimum input voltage. For a minimum VIN of 18 V, the primary output voltage (VOUT) must be no higher than 9 V. To generate an isolated output voltage of VOUT(ISO) = 12 V, a transformer turns ratio of 1 : 1.5 (N1 : N2) is selected. Using this turns ratio, calculate the required primary output voltage VOUT using Equation 22.

Equation 22. LM5160-Q1 eq19_Rev1_snvsa03.gif

The 0.7 V subtracted from VOUT(ISO) represents the forward voltage drop of the secondary rectifier diode. Fine tuning the primary side VOUT1 may be required to account for voltage errors due to the leakage inductance of the transformer and the resistance of the transformer windings and the low-side MOSFET of the LM5160-Q1.