A voltage regulator is a circuit that keeps a fixed output voltage, irrespective of changes to the input voltage or load conditions. From a power supply voltage regulator (VRs) keeps the voltages within a range that is quite compatible with the other electrical components.

Two major kinds of voltage regulators are linear and switching.

Linear Regulators

An active pass device is utilized by a linear voltage regulator which is then controlled by a high-gain operational amplifier. To maintain a constant output voltage, the linear regulator adjusts the pass device resistance and does it by comparing the internal voltage reference to the sampled output voltage and then driving the error to zero. Linear regulators are generally step-down converters; hence the output voltage is always lower than the input voltage. But this automatic voltage regulator even offers a few advantages: they are cost-efficient, generally easy to design, dependable, and offer low noise as well as a low output voltage ripple.