What Is a Voltage Regulator?
A voltage regulator (power supply integrated circuit) is an electronic component that controls the stable supply of power voltage when operating electronic equipment. For example, when various electronic devices are used by converting 100 VAC from a household outlet to DC voltage, they are controlled to maintain a constant output voltage, even if the load on the electronic devices varies. It also controls the output voltage to maintain stability even if the load fluctuates during use or if the operating environment changes, such as temperature.
Uses of Voltage Regulators
Voltage regulators are used in a variety of electronic devices. such as home appliances and mobile devices. Most modern home appliances are electronically controlled, and a variety of electronic circuits are used to control them. Portable devices are also equipped with various functions, such as displays, cameras, and sensors. To operate them, multiple power supply voltages must be stably supplied. In addition, more and more electronic devices are powered by rechargeable batteries, such as lithium-ion batteries, which are controlled by voltage regulators to ensure safe charging and stable output voltages.
Principle of Voltage Regulators
There are various types of voltage regulators, such as linear regulators, DC/DC converters, AC/DC converters, and rechargeable battery charge/discharge controllers. The basic principle of operation is that there is a control element between the input and output, and the power supply IC monitors the output voltage and controls the state of the control element so that the output maintains a constant voltage. Transistor elements, such as power MOSFETs and IGBTs, can be used as control elements.
In a linear regulator, the voltage applied to the gate of the transistor is varied according to changes in the output voltage, and the resistance of the transistor is controlled to maintain a constant output voltage.
In DC/DC converters and AC/DC converters, transistors are used as switching elements to control the ON/OFF of transistors so that the output voltage remains constant. The AC/DC converter also controls to improve the power factor.
In addition, the rechargeable battery charge control monitors not only voltage but also current and temperature, and controls the charge current to flow as much as possible within a safe range to enable rapid charging.