Switching power supply circuit capable of timing adjustment of signal
AssigneeRicoh Company, Ltd.
InventorsKatsuhisa Furuse, Yasuhiro Ishizaka, Senta Sekido
Life of this patent
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Abstract
A switching power supply circuit includes a plurality of switching regulators and a timing adjustment circuit. The plurality of switching regulators converts an input voltage input to an input terminal into a plurality of predetermined constant voltages, and outputs the plurality of predetermined constant voltages from a plurality of output terminals, respectively. The timing adjustment circuit adjusts phases of a plurality of pulse signals generated by the plurality of switching regulators so that the phases of the plurality of pulse signals are different from each other, and outputs the plurality of adjusted pulse signals to respective switch circuits of the plurality of switching regulators.
Claims13
A switching power supply circuit, comprising:
- a plurality of switching regulators configured to convert an input voltage input to an input terminal into a plurality of predetermined constant voltages and to output the plurality of predetermined constant voltages from a plurality of output terminals, respectively,
- each of the plurality of switching regulators comprising:
- a switch circuit configured to perform switching according to an input control signal;
- a coil charged with the input voltage by the switching performed by the switch circuit;
- and
- a control circuit configured to compare a voltage of a triangular wave signal with a voltage of an error signal, the error signal being obtained by amplifying a difference voltage corresponding to a difference between (a) a proportional voltage that is proportional to an output voltage output from the output terminal and (b) a predetermined reference voltage,
- the control circuit configured to output a pulse signal indicating a result of the comparison of said voltage of the triangular wave signal with said voltage of the error signal, to control the switching performed by the switch circuit;
- and
- a timing adjustment circuit configured to receive a plurality of said pulse signals generated by respective ones of the plurality of switching regulators, adjust phases of the plurality of pulse signals generated by the plurality of switching regulators to generate a plurality of adjusted pulse signals, such that phases of each of the plurality of adjusted pulse signals are different from each other, and to output the plurality of adjusted pulse signals to the respective switch circuits of the plurality of switching regulators.
The switching power supply circuit according to claim l, wherein the timing adjustment circuit detects edges of the plurality of pulse signals for turning off and interrupting the switch circuits, adjusts timings of the edges of the plurality of pulse signals to be shifted from each other by at least a predetermined time period, and outputs the plurality of adjusted pulse signals to the respective switch circuits.
The switching power supply circuit according to claim l, wherein the timing adjustment circuit adjusts the phases of the plurality of pulse signals to generate the plurality of adjusted signals, such that falling edges of each of the plurality of adjusted pulse signals are not within a predetermined time period of each other.
Dependencies are inferred from the claim text.