Low Dropout (LDO) Linear Regulators

An LDO (low-dropout) is a linear voltage regulator designed to operate with a very low input-to-output voltage differential (dropout voltage). It aims to minimize the power dissipated as heat on the device and increase conversion efficiency.

Our LDO regulator portfolio features best in class devices, including:

LDO regulators vs linear regulators

Linear voltage regulators are a cost-effective means to deliver a stable and regulated output voltage, with design simplicity and few external components. But LDO regulators provide the best cost-performance tradeoff in applications where the output current is less than few amps and the output voltage is close to that of the input.

LDO regulators vs switching converters

Compared to DC-DC switching converters, LDO regulators do not generate ripple, therefore they offer a very clean supply voltage. They require few design efforts thanks to the minimum number of external passive components needed.

low dropout ldo regulator

ST's LDO regulators offer an optimal combination of:

  • low dropout voltage
  • low quiescent current (low IQ)
  • fast transient response
  • low noise
  • and good ripple rejection

In particular, our ultra-low dropout regulators are ideal for battery-powered consumer and industrial applications, as well as portable healthcare devices, as a result of:

  • ultra-low quiescent current (down to 0.3 µA) which extends battery runtime
  • tiny package options, including the 0.65 x 0.65 mm flip-chip and 0.47 x 0.47 mm STSTAMP™ to achieve the smallest footprint

Signal fidelity is maintained over a wide range of input voltages and output currents all along the signal path, thanks to the high PSRR (power supply rejection rate) and low noise.

ldo regulators low dropout
STLQ020, our LDO drops the mic
with fast response and 300 nA of quiescent current

Find the best design solution thanks to high-performances Quad-LDO evaluation board

The STEVAL-LDO001V1 allows smart evaluation of four ST's high-performance low-dropout linear voltage regulators specially designed for extend battery life in portable smart devices. Thanks to state-of-the-art technologies, designs and innovative packaging, designers can select the best solution in terms of ultra-low quiescent current, ultra-low noise and high PSRR, automatic green mode and miniature packages such as Flip-Chip or ST STAMP™.

Ultra-tiny low-dropout regulator in breakthrough bumpless chip-scale package

The LDBL20 is a powerful 200 mA LDO in a tiny 0.47 x 0.47 mm innovative ST STAMP™ chip-scale package. The input voltage can range from 1.5 to 5.5 V, with 200 mV typical dropout. Rejection (PSRR) of 80 dB at 100 Hz and 50 dB at 100 kHz simplifies filtering over a wide frequency range to provide a stable rail for low-power circuitry in battery-operated applications. Quiescent current of 20 µA no-load, 100 µA full-load, and 0.3 µA in standby help maximize efficiency under all operating conditions. 
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