SLVSAW6H June   2011  – November 2024 LP2951-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 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. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    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. 7 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 (Legacy Chip)
            1. 7.2.1.1.1.1 ESR Range (Legacy Chip)
          2. 7.2.1.1.2 Recommended Capacitors (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 Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
      2. 8.1.2 Device Nomenclature
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
7.2.1.1.1 Recommended Capacitors (Legacy Chip)

Most tantalum or aluminum electrolytics are used at the input. Film-type capacitors also work but at higher cost. Ceramic capacitors are available for use at the output, but the low ESR (as low as 5mΩ to 10mΩ) potentially causes the output to not meet the minimum ESR requirement. If a ceramic capacitor is used, add a series resistor between 0.1Ω to 2Ω to meet the minimum ESR requirement.

Ceramic capacitors can be used, but because of the low ESR (as low as 5mΩ to 10mΩ), these capacitors can possibly not meet the minimum ESR requirement previously discussed. If a ceramic capacitor is used, a series resistor between 0.1Ω to 2Ω must be added to meet the minimum ESR requirement. In addition, ceramic capacitors have one glaring disadvantage that must be taken into account — a poor temperature coefficient, where the capacitance can vary significantly with temperature. For instance, a large-value ceramic capacitor (≥ 2.2μF) can lose more than half of the capacitance as temperature rises from 25°C to 85°C. Thus, a 2.2μF capacitor at 25°C drops well below the minimum CL required for stability as ambient temperature rises. For this reason, select an output capacitor that maintains the minimum 2.2μF required for stability for the entire operating temperature range.