What is the configuration of a PWM regulator circuit?
The figure below shows a simplified pulse-width modulated (PWM) controller employed in a switch-mode converter. In operation, a fraction of the dc output voltage feeds back to the error amplifier, which causes the comparator to control the ratio of the PWM ON and OFF times. The ratio of the ON time to the total period is the duty cycle. If the power drawn at the output changes, the feedback network adjusts the duty cycle to maintain the output voltage at the desired level. To generate the PWM signal, the error amplifier takes the difference of the feedback signal input and a stable voltage reference to produce an error voltage signal. The comparator compares the error amplifier output voltage with the sawtooth-shaped ramp from the oscillator, producing a modulated pulse width. The comparator output is applied to the switching logic, whose output goes to the output driver for the external power MOSFET. The switching logic provides the capability to enable or disable the PWM signal appli
