SNVS174I February   2003  – February 2015 LP3852 , LP3855

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematics
  5. 5 Revision History
  6. 6 Voltage Options
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagrams
    3. 9.3 Feature Description
      1. 9.3.1 SENSE Pin
      2. 9.3.2 SHUTDOWN (SD) Operation
      3. 9.3.3 Dropout Voltage
      4. 9.3.4 Reverse Current Path
      5. 9.3.5 Short-Circuit Protection
      6. 9.3.6 ERROR Flag Operation
    4. 9.4 Device Functional Modes
      1. 9.4.1 Operation with VOUT(TARGET) + 0.1 V ≤ VIN ≤ 7 V
      2. 9.4.2 Operation With SD Pin Control
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 External Capacitors
          1. 10.2.2.1.1 Input Capacitor
          2. 10.2.2.1.2 Output Capacitor
        2. 10.2.2.2 Operation with Ceramic Output Capacitors
        3. 10.2.2.3 Selecting A Capacitor
        4. 10.2.2.4 Capacitor Characteristics
          1. 10.2.2.4.1 Ceramic
          2. 10.2.2.4.2 Tantalum
          3. 10.2.2.4.3 Aluminum
        5. 10.2.2.5 Turnon Characteristics For Output Voltages Programmed to 2 V or Below
        6. 10.2.2.6 Output Noise
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
    3. 12.3 RFI and/or EMI Susceptibility
    4. 12.4 Power Dissipation/Heatsinking
      1. 12.4.1 Heatsinking TO-220 Package
      2. 12.4.2 Heatsinking TO-263 Package
  13. 13Device and Documentation Support
    1. 13.1 Related Links
    2. 13.2 Trademarks
    3. 13.3 Electrostatic Discharge Caution
    4. 13.4 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Input Supply Voltage: 2.5 V to 7 V
  • Ultra-Low Dropout Voltage
  • Stable with Selected Ceramic Capacitors
  • Low Ground-Pin Current
  • Load Regulation of 0.06%
  • 10-nA Quiescent Current in Shutdown Mode
  • Specified Output Current of 1.5 A DC
  • Output Voltage Accuracy ± 1.5%
  • ERROR Pin Indicates Output Status
  • SENSE Option Improves Load Regulation
  • 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 LP3852 and LP3855 series of fast ultra-low dropout linear regulators operate from a 2.5-V to 7-V input supply. A 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 LP3852 and LP3855 are developed on a CMOS process which allows low quiescent-current operation independent of output load current, typically 4 mA at 1.5-A load current. This CMOS process also allows the LP3852 and LP3855 to operate under extremely low dropout conditions, typically 24 mV at 150-mA load current and 240 mV at 1.5-A load current.

The LP3852 has an ERROR pin; it goes low when the output voltage drops 10% below nominal value. The LP3855 has a SENSE pin to improves regulation at remote loads.

The LP3852 and LP3855 are available with fixed output voltages from 1.8 V to 5 V with a specified accuracy of ±1.5% at room temperature, and ±3% over all conditions (varying line, load, and temperature). Contact Texas Instruments Sales for specific voltage option needs.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LP3852
LP3855		 SOT (5) 6.50 mm x 3.56 mm
TO-263 (5) 10.16 mm x 8.42 mm
TO-220 (5) 14.986 mm x 10.16 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

4 Simplified Schematics

LP3852 LP3855 20031001.gif
**SD and ERROR pins must be pulled high through a 10-kΩ pull-up resistor. Connect the ERROR pin to ground if this function is not used.
LP3852 LP3855 20031034.gif
**SD must be pulled high through a 10-kΩ pull-up resistor.