SLVS582K April   2006  – December 2024 LP2950 , LP2951

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  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 Receiving Notification of Documentation Updates
    3. 8.3 Device Nomenclature
    4. 8.4 Documentation Support
      1. 8.4.1 Related Documentation
    5. 8.5 Support Resources
    6. 8.6 Trademarks
    7. 8.7 Electrostatic Discharge Caution
    8. 8.8 Glossary
  10. Revision History
  11. 10Mechanical, Packaging, and Orderable Information

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

Thermal Shutdown

The device contains a thermal shutdown protection circuit to disable the device when the junction temperature (TJ) of the pass transistor rises to TSD(shutdown) (typical). Thermal shutdown hysteresis verifies that the device resets (turns on) when the temperature falls to TSD(reset) (typical).

The thermal time-constant of the semiconductor die is fairly short, thus the device cycles on and off when thermal shutdown is reached until power dissipation is reduced. Power dissipation during start up is potentially high from large VIN – VOUT voltage drops across the device or from high inrush currents charging large output capacitors. Under some conditions, the thermal shutdown protection disables the device before start-up completes.

For reliable operation, limit the junction temperature to the maximum listed in the Section 5.3 table. Operation above this maximum temperature causes the device to exceed operational specifications. Although the internal protection circuitry of the device is designed to protect against thermal overall conditions, this circuitry is not intended to replace proper heat sinking. Continuously running the device into thermal shutdown or above the maximum recommended junction temperature reduces long-term reliability.