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US 7,583,522 B2Granted
Low audible noise power supply method and controller therefor
AssigneeSemiconductor Components Industries, LLC
InventorsJefferson W. Hall, Christophe Basso
Life of this patent
Estimating the term…
Abstract
A power controller forms drive pulses that reduces audible noise under light load conditions.
Claims20
A method of forming a power system controller comprising:
- coupling a PWM controller to receive a reference signal having an asymmetrical waveform that increases continuously over a time interval that is greater than a switching cycle of a drive pulse formed by the PWM controller and responsively generate during the time interval a set of drive pulses having a plurality of drive pulses with increasing widths;
- and
- operably coupling the PWM controller to use the plurality of drive pulses during the time interval to control a power switch to form a plurality of current pulses having successively increasing amplitudes responsively to the increases in the reference signal wherein the successively increasing amplitudes form an asymmetrical signal envelope for the current pulses.
A method of forming a power supply controller comprising:
- configuring the power supply controller to organize output drive pulses of the power supply controller into a plurality of sets with each set having a plurality of drive pulses wherein the plurality of sets are spaced apart in time;
- configuring the power supply controller to form a reference signal having a value that varies continuously over a time interval that is greater than at least two drive pulse cycles of the plurality of drive pulses;
- and
- configuring the power supply controller to form the plurality of drive pulses within at least one set during the time interval to have successively increasing pulse widths in order to generate successive current pulses that increase in amplitude and form an asymmetrical signal envelope for the successive current pulses wherein at least a portion of the asymmetrical signal envelop increases in amplitude responsively to the increase in the amplitude of the successive current pulses.
1 more element
A power controller semiconductor device comprising:
- a control block coupled to generate an asymmetrical reference signal having a value that varies over a time interval wherein the time interval is greater than a switching cycle of the power controller;
- and
- a PWM controller coupled to receive the asymmetrical reference signal and generate during the time interval a set of drive pulses that includes a plurality of drive pulses, the plurality drive pulses having widths that increase successively over the time interval wherein the PWM controller is configured to use the plurality of drive pulses to control a power switch to generate a current having an asymmetrical signal envelope that increases in amplitude responsively to all of the plurality of drive pulses.
Dependencies are inferred from the claim text.