SNVS764Q January 2000  – December 2017 LP2950-N , LP2951-N

PRODUCTION DATA. 

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Voltage Options
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1Absolute Maximum Ratings
    2. 7.2ESD Ratings
    3. 7.3Recommended Operating Conditions
    4. 7.4Thermal Information: LP2950-N
    5. 7.5Thermal Information: LP2951-N
    6. 7.6Electrical Characteristics
    7. 7.7Typical Characteristics
  8. Detailed Description
    1. 8.1Overview
    2. 8.2Functional Block Diagrams
    3. 8.3Feature Description
      1. 8.3.1Fixed Voltage Options and Programmable Voltage Version
      2. 8.3.2High Accuracy Output Voltage
      3. 8.3.3Low Dropout Voltage
      4. 8.3.4Shutdown Mode
      5. 8.3.5Error Detection Comparator Output
      6. 8.3.6 Internal Protection Circuitry
        1. 8.3.6.1Short-Circuit Protection (Current Limit)
        2. 8.3.6.2Thermal Protection
      7. 8.3.7 Enhanced Stability
    4. 8.4Device Functional Modes
      1. 8.4.1Operation with 30 V ≥ VIN > VOUT(TARGET) + 1 V
      2. 8.4.2Operation with Shutdown Control
  9. Application and Implementation
    1. 9.1Application Information
    2. 9.2Typical Applications
      1. 9.2.1 1-A Regulator with 1.2-V Dropout
        1. 9.2.1.1Design Requirements
        2. 9.2.1.2Detailed Design Procedure
          1. 9.2.1.2.1Output Capacitor Requirements
          2. 9.2.1.2.2Input Capacitor Requirements
          3. 9.2.1.2.3Error Detection Comparator Output
          4. 9.2.1.2.4Programming the Output Voltage (LP2951-N)
          5. 9.2.1.2.5Reducing Output Noise
        3. 9.2.1.3Application Curves
      2. 9.2.2 300-mA Regulator with 0.75-V Dropout
      3. 9.2.3 Wide Input Voltage Range Current Limiter
      4. 9.2.4 Low Drift Current Source
      5. 9.2.5 5-V Current Limiter
      6. 9.2.6 Regulator with Early Warning and Auxiliary Output
      7. 9.2.7 Latch Off When Error Flag Occurs
      8. 9.2.8 2-A Low Dropout Regulator
      9. 9.2.9 5-V Regulator with 2.5-V Sleep Function
      10. 9.2.10Open Circuit Detector for 4 → 20-mA Current Loop
      11. 9.2.11Regulator with State-of-Charge Indicator
      12. 9.2.12Low Battery Disconnect
      13. 9.2.13System Overtemperature Protection Circuit
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1Layout Guidelines
    2. 11.2Layout Example
    3. 11.3WSON Mounting
  12. 12Device and Documentation Support
    1. 12.1Documentation Support
      1. 12.1.1Related Documentation
    2. 12.2Related Links
    3. 12.3Community Resources
    4. 12.4Trademarks
    5. 12.5Electrostatic Discharge Caution
    6. 12.6Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Features

  • Input Voltage Range: 2.3 V to 30 V
  • 5-V, 3-V, and 3.3-V Output Voltage Versions Available
  • High Accuracy Output Voltage
  • Ensured 100-mA Output Current
  • Extremely Low Quiescent Current
  • Low Dropout Voltage
  • Extremely Tight Load and Line Regulation
  • Very Low Temperature Coefficient
  • Use as Regulator or Reference
  • Needs Minimum Capacitance for Stability
  • Current and Thermal Limiting
  • Stable With Low-ESR Output Capacitors (10 mΩ to 6 Ω)
  • LP2951-N Versions Only:
    • Error Flag Warns of Output Dropout
    • Logic-Controlled Electronic Shutdown
    • Output Programmable From 1.24 V to 29 V

Applications

  • High-Efficiency Linear Regulator
  • Regulator with Undervoltage Shutdown
  • Low Dropout Battery-powered Regulator
  • Snap-ON/Snap-OFF Regulator
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LP2951 Simplified Schematic

LP2950-N LP2951-N simplified_schematic_2951_snvs764.gif

Description

The LP2950-N and LP2951-N are micropower voltage regulators with very low quiescent current (75 µA typical) and very low dropout voltage (typical 40 mV at light loads and 380 mV at 100 mA). They are ideally suited for use in battery-powered systems. Furthermore, the quiescent current of the device increases only slightly in dropout, prolonging battery life.

Careful design of the LP2950-N/LP2951-N has minimized all contributions to the error budget. This includes a tight initial tolerance (0.5% typical), extremely good load and line regulation (0.05% typical) and a very low output voltage temperature coefficient, making the part useful as a low-power voltage reference.

One such feature is an error flag output which warns of a low output voltage, often due to falling batteries on the input. It may be used for a power-on reset. A second feature is the logic-compatible shutdown input which enables the regulator to be switched on and off. Also, the part may be pin-strapped for a 5-V, 3-V, or 3.3-V output (depending on the version), or programmed from 1.24 V to 29 V with an external pair of resistors.

The LP2950-N is available in the surface-mount TO-252 package and in the popular 3-pin TO-92 package for pin-compatibility with older 5-V regulators. The 8-pin LP2951-N is available in plastic, ceramic dual-in-line, WSON, or metal can packages and offers additional system functions.

Device Information(1)

PART NUMBERPACKAGEBODY SIZE (NOM)
LP2950-NTO-92 (3)4.30 mm × 4.30 mm
TO-252 (3)9.91 mm × 6.58 mm
LP2951-NSOIC (8)4.90 mm × 3.91 mm
VSSOP (8)3.00 mm × 3.00 mm
WSON (8)4.00 mm × 4.00 mm
PDIP (8)9.81 mm × 6.35 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

LP2950-N Simplified Schematic

LP2950-N LP2951-N simplified_schematic_2950_snvs764.gif

Revision History

Changes from P Revision (May 2016) to Q Revision

  • Changed LP2951-N ESD parameter pin references and added SENSE pin row to LP2951-N ESD parameter in ESD Ratings tableGo

Changes from O Revision (December 2014) to P Revision

  • Added rows to ESD Ratings table to differentiate values for pins 3 and 7 of the LP2951-N deviceGo
  • Added footnotes 2 and 3 to both Thermal Information tables Go

Changes from N Revision (May 2013) to O Revision

  • Added Device Information and ESD Rating tables, Feature Description, Device Functional Modes, Application and Implementation, Power Supply Recommendations, Layout, Device and Documentation Support, and Mechanical, Packaging, and Orderable Information sections; moved some curves to Application Curves section; update pin names; change package nomenclature from National to TI Go

Changes from M Revision (April 2013) to N Revision

  • Changed layout of National Data Sheet to TI format Go