SLVS521I July   2004  – February 2025 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 Diagrams
    3. 6.3 Feature Description
      1. 6.3.1 Output Enable
      2. 6.3.2 Dropout Voltage
      3. 6.3.3 Current Limit
        1. 6.3.3.1 Current Limit (Legacy Chip)
        2. 6.3.3.2 Current Limit (New Chip)
      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 Normal Operation
      2. 6.4.2 Dropout Operation
      3. 6.4.3 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 (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 (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
          1. 7.1.2.2.1 Output Capacitor (Legacy Chip)
          2. 7.1.2.2.2 Output Capacitor (New Chip)
      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
    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 Nomenclature
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 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

3 Description

The LP2981 and LP2981A (LP2981x) are fixed-output, low-dropout (LDO) voltage regulators supporting an input voltage range from 2.5V to 16V (for new chip only) and up to 100mA of load current. The LP2981x support an output range of 1.2V to 5.0V (new chip).

Additionally, the LP2981x (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 75dB at 1kHz and 45dB at 1MHz to help attenuate the switching frequency of an upstream DC/DC converter and minimize post regulator filtering.

In the new chip, the internal soft-start mechanism reduces 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)
LP2981x DBV (SOT-23, 5) 2.9mm × 2.8mm
(1) For more information, see the Mechanical, Packaging, and Orderable Information.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.

 

LP2981 LP2981A Typical Application CircuitTypical Application Circuit
LP2981 LP2981A Dropout Voltage vs Temperature (New Chip)Dropout Voltage vs Temperature (New Chip)