Switching power source apparatus
AssigneeSanken Electric Co., Ltd.
InventorMasaru Nakamura
Life of this patent
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Abstract
A switching power source apparatus includes a high-side MOSFET 11 connected to an input voltage, a ramp signal generator 18 to generate a ramp signal in synchronization with a switching frequency of the high-side MOSFET 11, an amplitude signal generator to generate an amplitude signal Comp corresponding to an amplitude of the ramp signal, a superposing circuit 3 to generate a second ramp signal having a positive inclination corresponding to the amplitude and frequency of the ramp signal and provide a superposed signal by superposing the second ramp signal on a first reference voltage, a controller 1 to control the ON timing and ON width of the high-side MOSFET 11, and a sudden heavy load detector 23 to detect if light load changes to heavy load, and if detects such a change, widen the ON width of the high-side MOSFET 11.
Claims13
A switching power source apparatus comprising:
- a high-side switch connected to an input voltage;
- a ramp signal generator configured to generate a ramp signal in synchronization with a switching frequency of the high-side switch;
- an amplitude signal generator configured to generate an amplitude signal corresponding to an amplitude of the ramp signal;
- a superposing circuit configured to generate a second ramp signal having a positive inclination corresponding to the amplitude and frequency of the ramp signal and provide a superposed signal by superposing the second ramp signal on a first reference voltage;
- a controller configured to compare the superposed signal with a feedback signal corresponding to an output voltage, and if the feedback signal is lower than the superposed signal, control the ON timing of the high-side switch so that the high-side switch turns on, the controller being also configured to control the ON width of the high-side switch according to the amplitude signal, input voltage, and output voltage;
- and
- a sudden heavy load detector configured to detect if light load changes to heavy load according to the superposed signal and feedback signal, and if detects such a change, widen the ON width of the high-side switch.
Dependencies are inferred from the claim text.