Post Date : Feb 16, 2023 / Last updated : Apr 06, 2023

Voltage regulator operation image

This section gives a simple explanation of how linear voltage regulators control the output voltage to keep it constant.

For the voltage regulator basic principle, image inputting variable resistance to adjust the output voltage in the IC.

The resistance value of this variable resistance is changed in accordance with the input voltage and output current to adjust the output voltage to keep it constant.

This variable resistance is called a driver transistor/FET and is composed of a transistor and a FET. How the resistance value of the driver transistor/FET is controlled is explained in “Voltage Regulator Operation Principles and Configuration.”

NPN Emitter Follower Output
NPN Darlington Output
PNP Transistor Output
MOSFET Output

Conclusion

The voltage regulator basic principle is that the variable resistance (driver transistor/FET) is adjusted to control the output voltage to keep it constant.