DC-DC controller and control method thereof

摘要

A DC-DC controller and a control method thereof are provided. The DC-DC controller is coupled to an output stage. The output stage receives an input voltage and provides an output voltage. The DC-DC controller includes a transient boost circuit, a ramp oscillator, a combination logic circuit, a first comparator and a pulse width modulation (PWM) generator. The transient boost circuit generates an adjusting signal according to a variation of the output voltage. The combination logic circuit controls the ramp oscillator to generate a ramp signal according to the adjusting signal. The first comparator generates a first signal according to the ramp signal and an outputted feedback voltage related to the output voltage. The PWM generator generates a PWM signal according to the first signal, so as to control the operations of the output stage.

主权项

1. A direct current (DC)-DC controller coupled to an output stage where the output stage receives an input voltage and provides an output voltage, the DC-DC controller comprising:
a transient boost circuit, generating an adjusting signal according to a variation of the output voltage; a ramp oscillator; a combination logic circuit, coupled to the transient boost circuit and the ramp oscillator, and providing a ramp signal according to the adjusting signal and an output of the ramp oscillator, wherein when the adjusting signal has a first logic level, the combination logic circuit adjusts the ramp signal so that the ramp signal is maintained at a first predetermined level for a predetermined time, wherein the first predetermined level is lower than a level of an error signal related to the output voltage; a first comparator, coupled to the combination logic circuit, and generating a first signal according to the error signal and the ramp signal; and a pulse width modulation (PWM) generator, coupled to the first comparator, and generating a PWM signal to control the operation of the output stage according to the first signal.