1-3. What is an LDO regulator?

An LDO regulator is a type of semiconductor voltage regulator that is used when the required output voltage differs from the input voltage.
Suppose, for example, that the input voltage is 5 V and that the required output voltage is 3 V. In such cases, LDO regulators provide a simple and inexpensive solution for power supply regulation.
A voltage regulator with a small difference in voltage between input and output is called an LDO regulator. LDO stands for low dropout; an LDO regulator is a type of linear regulator with a low input-output voltage differential.
This article describes why electronic devices require LDO regulators for stable operation and provides an overview of them.