Voltage converter

摘要

A voltage converter is disclosed. The voltage converter includes a constant on time signal generator, a first and second transistors, an inductor, a feedback circuit and a ripple injection circuit. The constant on time signal generator generates a first and second driving signals for driving the first and second transistors. The voltage converter generates an output signal at an output end thereof. The feedback circuit divides the output signal to generate a feedback signal at a feedback end of the voltage converter. The ripple injection circuit gets the voltage of the feedback end and the voltage of the phase end to generate a injection signal. The constant on time signal generator generates the first and second driving signals according to the injection signal, the output signal and a reference signal.

主权项

1. A voltage converter, comprising:
a constant on time signal generator, for generating a first driving signal and a second driving signal; a first transistor, comprising a first end for receiving a power supply voltage, a second end coupled to a phase end of the voltage converter, and a control end for receiving the first driving signal; a second transistor, comprising a first end coupled to the phase end, a second end coupled to a reference ground voltage, and a control end for receiving the second driving signal; an inductor, connected in series between the phase end and an output end of the voltage converter, an output signal being generated at the output end of the voltage converter; a feedback circuit, for dividing the output signal to generate a feedback signal at a feedback end of the voltage converter; and a ripple injection circuit, coupled to the feedback end and the phase end, and for getting a voltage of the feedback end and a voltage of the phase end to generate a injection signal according to a voltage difference between the voltage of the feedback end and the voltage of the phase end; wherein the constant on time signal generator generates the first and the second driving signals according to the injection signal, the output signal and a reference signal, wherein the ripple injection circuit comprises:
a first resistor, comprising a first end coupled to the phase end;a first capacitor, comprising a first end coupled to a second end of the first resistor, and a second end receiving the feedback signal;a second resistor, comprising a first end coupled to the second end of the first resistor;a second capacitor, comprising a first end coupled to a second end of the second resistor, and a second end receiving the feedback signal; andan operational amplifier, comprising a first input end, a second input end and an output end, the first input end and the second input end being respectively coupled to the first end and the second end of the second resistor, wherein the operational amplifier generates an injection signal according to the voltage difference, and transmits the injection signal to the constant on time signal generator through the output end thereof.