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.
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.
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.