Q. How do voltage regulator ICs work?

Answer

A voltage regulator is a device that produces an output voltage that is fixed at a certain magnitude and does not vary no matter what changes are made to the input voltage or load circumstances. Linear regulators and switching regulators are the two kinds of voltage regulators. A high gain differential amplifier drives an active pass device used by a linear regulator. It compares the voltage at the output with a very accurate reference value and then adjusts the pass device such that the output voltage remains the same.