A voltage regulator is a chip or module that controls the output voltage of a circuit to maintain a constant level. The basic function of a voltage regulator is to compare the output voltage to a reference voltage and adjust the output voltage to match the reference voltage. The reference voltage can be a fixed or variable value depending on the driver chip.
There are two main types of voltage regulators: linear voltage regulators and switching voltage regulators.
Both types of voltage regulators have a feedback loop that senses the output voltage and compares it to the reference voltage. Depending on the design and the type of voltage regulator it is, it will adjust the current flow or switching to maintain the output voltage to the desired level.
It is important to choose a voltage regulator that is appropriate for your specific application, and to carefully review the manufacturer's specifications to ensure that it will perform as expected under the specific conditions of your circuit.
There are a few things to be aware of when using voltage regulators, including:
A low dropout voltage regulator (LDO) is a type of voltage regulator that can provide a stable output voltage with a relatively small voltage difference (i.e., "dropout voltage") between the input and output. This makes them particularly useful in applications where the input voltage is close to the desired output voltage, or where a precise output voltage is needed.
LDOs are typically linear regulators, which means that they work by adjusting the current flowing through a pass transistor to control the output voltage. Because the pass transistor is operating in its linear region, the output voltage is directly proportional to the input voltage. The voltage difference between the input and output is a result of the voltage drop across the pass transistor and any other internal losses in the regulator.
LDOs typically have dropout voltage between around 100mV to 2V, which is why they are considered as low dropout, this allow them to provide a stable output voltage even when the input voltage is only slightly higher than the desired output voltage.