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Linear & low-dropout (LDO) regulators

LP2981

ACTIVE

100-mA, 16-V, low-dropout voltage regulator with enable

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Data sheet

LP2981

ACTIVE
Data sheet Order now

Product details

Rating Catalog Vin (max) (V) 16 Vin (min) (V) 2.2 Iout (max) (A) 0.1 Output options Fixed Output Vout (max) (V) 5 Vout (min) (V) 2.8 Fixed output options (V) 1.8, 2.5, 2.8, 2.9, 3, 3.3, 3.6, 5 Noise (µVrms) 160 PSRR at 100 KHz (dB) 41 Iq (typ) (mA) 0.065 Features Enable Thermal resistance θJA (°C/W) 205 Load capacitance (min) (µF) 2.2 Regulated outputs (#) 1 Accuracy (%) 6 Dropout voltage (Vdo) (typ) (mV) 200 Operating temperature range (°C) -40 to 125
Rating Catalog Vin (max) (V) 16 Vin (min) (V) 2.2 Iout (max) (A) 0.1 Output options Fixed Output Vout (max) (V) 5 Vout (min) (V) 2.8 Fixed output options (V) 1.8, 2.5, 2.8, 2.9, 3, 3.3, 3.6, 5 Noise (µVrms) 160 PSRR at 100 KHz (dB) 41 Iq (typ) (mA) 0.065 Features Enable Thermal resistance θJA (°C/W) 205 Load capacitance (min) (µF) 2.2 Regulated outputs (#) 1 Accuracy (%) 6 Dropout voltage (Vdo) (typ) (mV) 200 Operating temperature range (°C) -40 to 125
SOT-23 (DBV) 5 8.12 mm² (2.9 mm × 2.8 mm)
  • Input voltage (VIN) range:
    • Legacy chip: 2.2V to 16V
    • New chip: 2.5V to 16V
  • Output voltage (VOUT) range: 1.2V to 5.0V
  • Output voltage (VOUT) accuracy:
    • ±0.75% for A-grade legacy chip
    • ±1.25% for standard-grade legacy chip
    • ±0.5% for new chip (A-grade and standard grade)
  • Output Voltage (VOUT) accuracy over load, and temperature: ±1% (new chip)
  • Output current: Up to 100mA
  • Low IQ (new chip): 69µA at ILOAD = 0mA
  • Low IQ (new chip): 620µA at ILOAD = 100mA
  • Shutdown current over temperature:
    • < 1µA (legacy chip)
    • ≤ 1.75µA (new chip)
  • Output current limiting and thermal protection
  • Stable with 2.2µF ceramic capacitors (new chip)
  • High PSRR (new chip):
    • 75dB at 1kHz, 45dB at 1MHz
  • Operating junction temperature: –40°C to +125°C
  • Package: 5-pin SOT-23 (DBV)
  • Input voltage (VIN) range:
    • Legacy chip: 2.2V to 16V
    • New chip: 2.5V to 16V
  • Output voltage (VOUT) range: 1.2V to 5.0V
  • Output voltage (VOUT) accuracy:
    • ±0.75% for A-grade legacy chip
    • ±1.25% for standard-grade legacy chip
    • ±0.5% for new chip (A-grade and standard grade)
  • Output Voltage (VOUT) accuracy over load, and temperature: ±1% (new chip)
  • Output current: Up to 100mA
  • Low IQ (new chip): 69µA at ILOAD = 0mA
  • Low IQ (new chip): 620µA at ILOAD = 100mA
  • Shutdown current over temperature:
    • < 1µA (legacy chip)
    • ≤ 1.75µA (new chip)
  • Output current limiting and thermal protection
  • Stable with 2.2µF ceramic capacitors (new chip)
  • High PSRR (new chip):
    • 75dB at 1kHz, 45dB at 1MHz
  • Operating junction temperature: –40°C to +125°C
  • Package: 5-pin SOT-23 (DBV)

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.

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.
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Technical documentation

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Top documentation Type Title Format options Date
* Data sheet LP2981x 100mA, Low-Dropout Regulator in SOT-23 Package datasheet (Rev. I) PDF | HTML Feb 11, 2025
Circuit design Isolated power supply, low-noise circuit: 5V, 100mA (Rev. B) PDF | HTML Sep 23, 2024
Application note LDO Noise Demystified (Rev. B) PDF | HTML Aug 18, 2020
Application note ESR, Stability, and the LDO Regulator (Rev. A) Jan 7, 2020
Application note A Topical Index of TI LDO Application Notes (Rev. F) Jun 27, 2019
Application note Fundamental Theory of PMOS LDO Voltage Regulators (Rev. A) Aug 17, 2018
Application note LDO PSRR Measurement Simplified (Rev. A) PDF | HTML Aug 9, 2017
Application note A Topical Index of TI Supply Voltage Supervisor (SVS) Application Notes Jun 15, 2015
Analog design Journal Techniques for accurate PSRR measurements Oct 28, 2013
Application note AN-1028 Maximum Power Enhancement Techniques for Power Packages (Rev. B) May 6, 2013
Application note AN-1482 LDO Regulator Stability Using Ceramic Output Capacitors (Rev. A) Apr 25, 2013
Application note AN-1815 LDOs Ease the Stress of Start-Up (Rev. A) Apr 24, 2013
Application note AN-1950 Silently Powering Low Noise Applications (Rev. A) Apr 22, 2013
Application note LDO Performance Near Dropout Oct 8, 2010
Application note 3.6V – 5.5V Input, LDO with Dual-Level Output Reference Design for MSP430 (Rev. A) Jun 14, 2010
Application note 3.6V – 5.5V Input, LDO Reference Design for MSP430 (Rev. A) Jun 14, 2010
Application note Packaging Limits Range of Linear Regulators May 8, 2010
Application note Simple Power Solution Using LDOs for the DM365 (Rev. A) Sep 11, 2009
Application note Digital Designer's Guide to Linear Voltage Regulators & Thermal Mgmt (LDO) (Rev. A) Jun 4, 2008
Application note Linear and Switching Voltage Regulator Fundamental Part 1 Mar 21, 2007
Application note Ceramic Capacitors Replace Tantalum Capacitors in LDOs (Rev. A) Oct 13, 2006
Application note Understanding LDO Dropout May 9, 2005
More literature LP2981/85 Product Clip Sep 9, 2004
Application note Extending the Input Voltage Range of an LDO Regulator Aug 16, 2002
Application note Understanding the Terms and Definitions of LDO Voltage Regulators Oct 21, 1999
Application note Technical Review of Low Dropout Voltage Regulator Operation And Performance Aug 30, 1999
Application brief Low Power 150-mA LDO Linear Regulators. Extended Output Voltage Adjustment Range Jun 11, 1999

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