SNVS225H February   2003  – June 2015 LP3871 , LP3874

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Shutdown (SD)
      2. 7.3.2 Short-Circuit Protection
      3. 7.3.3 Low Dropout Voltage
      4. 7.3.4 SENSE Pin
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
      3. 7.4.3 ERROR Flag Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Reverse Current Path
      2. 8.1.2 Turnon Characteristics for Output Voltages Programmed To 2 V or Below
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 External Capacitors
        2. 8.2.2.2 Selecting a Capacitor
        3. 8.2.2.3 Capacitor Characteristics
          1. 8.2.2.3.1 Ceramic
          2. 8.2.2.3.2 Tantalum
          3. 8.2.2.3.3 Aluminum
        4. 8.2.2.4 RFI/EMI Susceptibility
        5. 8.2.2.5 Output Noise
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
    1. 9.1 Power Dissipation
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Related Links
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • Input Voltage: 2.5 V to 7 V
  • Ultra-Low-Dropout Voltage
  • Low Ground Pin Current
  • Load Regulation of 0.04%
  • 10-nA Quiescent Current in Shutdown Mode
  • Specified Output Current of 0.8-A DC
  • Output Voltage Accuracy ±1.5%
  • ERROR Flag Indicates Output Status
  • SENSE Option Improves Load Regulation
  • Minimum Output Capacitor Requirements
  • Overtemperature/Overcurrent Protection
  • −40°C to +125°C Junction Temperature Range

2 Applications

  • Microprocessor Power Supplies
  • GTL, GTL+, BTL, and SSTL Bus Terminators
  • Power Supplies for DSPs
  • SCSI Terminator
  • Post Regulators
  • High-Efficiency Linear Regulators
  • Battery Chargers
  • Other Battery-Powered Applications

3 Description

The LP3871 and LP3874 series of fast ultra-low-dropout linear regulators operate from a 2.5-V to 7-V input supply. Wide range of preset output voltage options are available. These ultra-low-dropout linear regulators respond very quickly to step changes in load, which makes them suitable for low voltage microprocessor applications. The devices are developed on a CMOS process which allows low quiescent current operation independent of output load current. This CMOS process also allows the LP3871 and LP3874 to operate under extremely low dropout conditions.

Dropout Voltage: Ultra-low-dropout voltage; typically 24 mV at 80-mA load current and 240 mV at 0.8-A load current.

Ground Pin Current: Typically 6 mA at 0.8-A load current.

Shutdown Mode: Typically 10-nA quiescent current when the SD pin is pulled low.

ERROR Flag: ERROR flag goes low when the output voltage drops 10% below nominal value.

SENSE: SENSE pin improves regulation at remote loads.

Precision Output Voltage: Multiple output voltage options are available ranging from 1.8 V to 5 V with a ensured accuracy of ±1.5% at room temperature, and ±3% over all conditions (varying line, load, and temperature).

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LP3871
LP3874		 SOT-223 (5) 6.50 mm x 3.56 mm
DDPAK/ TO-263 (5) 10.16 mm x 8.42 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Applications

LP3871 LP3874 20063301.png
*SD and ERROR pins must be pulled high through a 10-kΩ pullup resistor. Connect the ERROR pin to ground if this function is not used. See Application and Implementation for more information.
LP3871 LP3874 20063345.png
*SD must be pulled high through a 10-kΩ pullup resistor. See Application and Implementation for more information.