SLVS582K April   2006  – December 2024 LP2950 , LP2951

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 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. 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 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. 8 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. 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 for the 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.