JAJSML9K April   2006  – December 2024 LP2950 , LP2951

PRODUCTION DATA  

  1.   1
  2. 特長
  3. アプリケーション
  4. 概要
  5. Pin Configuration and Functions
  6. 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 (Both Legacy and New Chip)
    6. 5.6 Timing Requirements (New Chip only)
    7. 5.7 Typical Characteristics
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagrams
    3. 6.3 Feature Description
      1. 6.3.1 Output Enable
      2. 6.3.2 Dropout Voltage
      3. 6.3.3 Current Limit
      4. 6.3.4 Undervoltage Lockout (UVLO)
      5. 6.3.5 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
  8. Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Reverse Current
      2. 7.1.2 Input and Output Capacitor Requirements
      3. 7.1.3 Estimating Junction Temperature
      4. 7.1.4 Power Dissipation (PD)
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
        1. 7.2.1.1 Recommended Capacitor Types
          1. 7.2.1.1.1 Recommended Capacitors for the Legacy Chip
            1. 7.2.1.1.1.1 ESR Range (Legacy Chip)
          2. 7.2.1.1.2 Recommended Capacitors for the New Chip
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Feedback Resistor Selection
        2. 7.2.2.2 Feedforward Capacitor
      3. 7.2.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
    2. 8.2 ドキュメントの更新通知を受け取る方法
    3. 8.3 Device Nomenclature
    4. 8.4 Documentation Support
      1. 8.4.1 Related Documentation
    5. 8.5 サポート・リソース
    6. 8.6 Trademarks
    7. 8.7 静電気放電に関する注意事項
    8. 8.8 用語集
  10. Revision History
  11. 10Mechanical, Packaging, and Orderable Information
Recommended Capacitors for the New Chip

The new chip requires an output capacitor of at least 1μF for stability and an equivalent series resistance (ESR) between 0Ω and 2Ω. Without the output capacitor, the regulator oscillates. For best transient performance, use X5R- and X7R-type ceramic capacitors because these capacitors have minimal variation in value and ESR over temperature. When choosing a capacitor for a specific application,be mindful of the DC bias characteristics for the capacitor. Higher output voltages cause a significant derating of the capacitor. For best performance, the maximum recommended output capacitor is 100μF. An input capacitor is not required for stability, however, good analog practice is to connect a capacitor (500nF or higher) between the GND and IN pin . Some input supplies have a high impedance, thus placing the input capacitor on the input supply helps reduce input impedance. This capacitor counteracts reactive input sources and improves transient response, input ripple, and PSRR. If the input supply has a high impedance over a large range of frequencies, use several input capacitors in parallel to lower the impedance over frequency. Use a higher-value capacitor if large, fast rise-time load transients are anticipated, or if the device is located several inches from the input power source.