JAJSEP3C September   2017  – March 2018 LMZM33603

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
    1.     概略回路図
  3. 3 概要
    1.     安全動作領域
  4. 4 改訂履歴
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Switching Characteristics
    7. 6.7 Typical Characteristics (VIN = 5 V)
    8. 6.8 Typical Characteristics (VIN = 12 V)
    9. 6.9 Typical Characteristics (VIN = 24 V)
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Adjusting the Output Voltage
      2. 7.3.2  Feed-Forward Capacitor, CFF
      3. 7.3.3  Output Current vs Output Voltage
      4. 7.3.4  Voltage Dropout
      5. 7.3.5  Switching Frequency (RT)
      6. 7.3.6  Synchronization (SYNC)
      7. 7.3.7  Input Capacitors
      8. 7.3.8  Output Capacitors
      9. 7.3.9  Output On/Off Enable (EN)
      10. 7.3.10 Programmable Undervoltage Lockout (UVLO)
      11. 7.3.11 Power Good (PGOOD)
      12. 7.3.12 Overcurrent Protection (OCP)
      13. 7.3.13 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Shutdown Mode
  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 Setpoint
        3. 8.2.2.3 Feed-Forward Capacitor (CFF)
        4. 8.2.2.4 Setting the Switching Frequency
        5. 8.2.2.5 Input Capacitors
        6. 8.2.2.6 Output Capacitor Selection
        7. 8.2.2.7 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
    3. 10.3 Theta JA vs PCB Area
    4. 10.4 EMI
      1. 10.4.1 EMI Plots
    5. 10.5 Package Specifications
  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. 11.1.2 WEBENCH®ツールによるカスタム設計
    2. 11.2 関連資料
    3. 11.3 ドキュメントの更新通知を受け取る方法
    4. 11.4 コミュニティ・リソース
    5. 11.5 商標
    6. 11.6 静電気放電に関する注意事項
    7. 11.7 Glossary
  12. 12メカニカル、パッケージ、および注文情報

7.3.9 Output On/Off Enable (EN)

The voltage on the EN/SYNC pin provides electrical ON/OFF control of the device. Once the EN pin voltage exceeds the threshold voltage, the device starts operation. If the EN pin voltage is pulled below the threshold voltage, the regulator stops switching and enters low quiescent current state.

The EN pin cannot be open circuit or floating. The simplest way to enable the operation of the LMZM33603 is to connect the EN pin to VIN directly as shown in Figure 27. This allows self-start-up of the LMZM33603 when VIN is within the operation range.

If an application requires controlling the EN pin, an external logic signal can be used to drive EN/SYNC pin as shown in Figure 28. Applications using an open drain/collector device to interface with this pin require a pullup resistor to a voltage above the enable threshold.

Figure 29 and Figure 30 show typical turn-ON and turn-OFF waveforms using the enable control.

LMZM33603 ZZtopEN2.gifFigure 27. Enabling the Device
LMZM33603 ZZtopENlogic2.gifFigure 28. Typical Enable Control
LMZM33603 ENstart.gifFigure 29. Enable Turn-ON
LMZM33603 ENshutdown.gifFigure 30. Enable Turn-OFF