Patent ID: 8049480
Filing Date: 2011-11-01
Classification: H02M

Abstract:
1. A comparator-system DC-DC converter, comprising: a voltage conversion section which comprises a switching element and generates an output voltage obtained by voltage-converting an input voltage by controlling the switching element in accordance with a control signal; and a control unit which generates the control signal for stabilizing the output voltage of the voltage conversion section, wherein the control unit comprises: a comparator section which compares the output voltage of the voltage conversion section and a reference voltage, and determines a predetermined ON width of an ON pulse or the OFF width of an OFF pulse of the control signal; and a counter section which counts a number of at least either one of the ON pulses and OFF pulses of the control signal, and counts a number of pulses of a reference clock in a predetermined period that includes a plurality of pulses of the reference clock to change an analog level or a digital value of a frequency control signal that adjusts the predetermined ON width so that the ratio between the count value of the control signal and the count value of the reference clock is M:N, where M and N are natural numbers, wherein the count value of the control signal indicates the number of said pulses of the control signal, and wherein the count value of the reference clock indicates the number of said pulses of the reference clock.