Patent ID: 8957661
Filing Date: 2015-02-17
Classification: H02M,Y02B

Abstract:
1. A DC-DC converter, comprising: a switch unit configured to generate output voltage for driving a load; an output voltage monitoring unit including a reference voltage generator generating reference voltage and a reference voltage capacitor maintaining the reference voltage when power of the reference voltage generator is interrupted and configured to generate a signal for setting the output voltage as the reference voltage; a switch controlling unit configured to control the switch unit by being operated in a pulse width modulation (PWM) mode or a pulse frequency modulation (PFM) mode by using the signal of the output voltage monitoring unit; and a mode determining and power interrupting unit configured to set an operating mode of the switch controlling unit as the PWM mode or the PFM mode according to a magnitude of the load and interrupt power of the reference voltage generator when operated in the PFM mode, wherein the output voltage monitoring unit includes an error amplifier configured to amplify a difference value between the output voltage and the reference voltage and generate a signal indicating the amplified difference value and a comparator configured to generate a signal by comparing magnitudes of the output voltage and the reference voltage.