Patent ID: 6057675
Filing Date: 2000-05-02
Classification: H02M,Y02B

Abstract:
A DC/DC converter, which has a switch and an inductor connected to the switch, for generating a predetermined output voltage from a supplied input voltage, comprising:a control signal generating circuit which generates a control signal based on a difference between an output voltage or a voltage proportional to the output voltage and a reference voltage;a detecting circuit which detects an inductor current flowing through the inductor;an oscillator which generates a signal of a predetermined cycle;a first comparing signal generating circuit which generates a first comparing signal that synchronizes with the signal of the predetermined cycle;a latch circuit which selectively holds either a set state or a reset state;a driving circuit which drives the switch based on a state held by the latch circuit;a capacitor which stores an electric charge which is used when said driving circuit holds the switch ON;a second comparing signal generating circuit which generates a second comparing signal based on the state held by said latch circuit; anda reset signal generating circuit which generates a reset signal based on the control signal, the inductor current, the first comparing signal, and the second comparing signal, whereinsaid latch circuit is set by the signal of the predetermined cycle, and is reset by the reset signal.