SLVS521H July   2004  – December 2023 LP2981 , LP2981A

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
    6. 5.6 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
      6. 6.3.6 Output Pulldown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Device Functional Mode Comparison
      2. 6.4.2 Normal Operation
      3. 6.4.3 Dropout Operation
      4. 6.4.4 Disabled
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Recommended Capacitor Types
        1. 7.1.1.1 Recommended Capacitors for the Legacy Chip
          1. 7.1.1.1.1 Tantalum Capacitors
          2. 7.1.1.1.2 Ceramic Capacitors
          3. 7.1.1.1.3 Aluminum Capacitors
        2. 7.1.1.2 Recommended Capacitors for the New Chip
      2. 7.1.2 Input and Output Capacitor Requirements
        1. 7.1.2.1 Input Capacitor
        2. 7.1.2.2 Output Capacitor
      3. 7.1.3 Estimating Junction Temperature
      4. 7.1.4 Power Dissipation (PD)
      5. 7.1.5 Reverse Current
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 ON and OFF Input Operation
      3. 7.2.3 Application Curves
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Nomenclature
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

3 Description

The LP2981 is a fixed-output, low-dropout (LDO) voltage regulator supporting an input voltage range from 2.5 V to 16 V (for new chip only) and up to 100 mA of load current. The LP2981 supports an output range of 1.2 V to 5.0 V (new chip).

Additionally, the LP2981 (new chip) has a 1% output accuracy across load and temperature that can meet the needs of low-voltage microcontrollers (MCUs) and processors.

In the new chip, wide bandwidth PSRR performance is 75 dB at 1 kHz and 45 dB at 1 MHz to help attenuate the switching frequency of an upstream DC/DC converter and minimize post regulator filtering.

The internal soft-start time and current-limit protection reduce inrush current during start up, thus minimizing input capacitance. Standard protection features, such as overcurrent and overtemperature protection, are included.

Package Information
PART NUMBER PACKAGE(1) PACKAGE SIZE(2)
LP2981 SOT-23 (5) 2.90 mm × 2.80 mm
LP2981A
(1) For more information, see Section 12.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
GUID-20231126-SS0I-089W-ZB78-PHKJF6MKWCVZ-low.svgTypical Application Circuit
GUID-20231125-SS0I-VSQP-FQNP-PZGGFBP5BGGQ-low.svgDropout Voltage vs Temperature (New Chip)