DC-DC Buck Converter: Working Principle & PWM Control

The working principle of a DC-DC buck converter controlled by a PWM signal is based on the principle of pulse width modulation (PWM). In this type of converter, a high-frequency switching signal is applied to a transistor, which is used to control the amount of voltage that is transferred from the input to the output.

The PWM signal is generated by a control circuit that varies the duty cycle of the switching signal. The duty cycle is the ratio of the on-time to the total time of the switching signal. By varying the duty cycle, the output voltage can be regulated.

When the switching transistor is turned on, the input voltage is applied to the output load, causing the output voltage to increase. When the transistor is turned off, the energy stored in the inductor is transferred to the output load, causing the output voltage to decrease. By adjusting the duty cycle, the average output voltage can be controlled.

Overall, the DC-DC buck converter controlled by a PWM signal is an efficient and effective way to convert high voltage inputs to lower voltages required by electronic devices.