Single ended flyback power supply controllers with integrator to integrate the difference between feedback signal a reference signal
First Claim
1. A switch mode power supply (SMPS) controller for regulating the output voltage of an SMPS in response to a feedback signal from a winding of a magnetic energy storage device forming part of an output circuit of the SMPS, the SMPS controller comprising:
- a reference level input to receive an output reference level signal;
an input to receive said feedback signal, said feedback signal being responsive to a voltage on said winding of said magnetic energy storage device;
an integrator to integrate a difference between said feedback signal and a first fixed reference level signal;
a first comparator to compare an output of said integrator with a second fixed reference level signal and to provide an output responsive to said comparison for regulating said SMPS output voltage;
a second comparator to compare a signal derived from said feedback signal with a third reference level signal derived from said output reference level signal, at a time when said first comparator indicates that said integrator output is substantially equal to said second fixed reference level signal; and
a controller output coupled to an output of said second comparator to provide a regulation signal for controlling said SMPS to regulate said SMPS output voltage.
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Accused Products
Abstract
This invention relates to SMPS controllers employing primary side sensing to detect a point of zero magnetic flux, at which the output voltage of the SMPS may be sampled accurately on the primary side. We describe a switch mode power supply (SMPS) controller for regulating the output voltage of an SMPS is response to a feedback signal from an auxilliary winding of a magnetic energy storage device forming part of an output circuit of the SMPS, the SMPS controller comprising: a reference level input to receive an output reference level signal; an input to receive said feedback signal, said feedback signal being responsive to a voltage on said auxilliary winding of said magnetic energy storage device; an integrator to integrate a difference between said feedback signal and a first fixed reference level signal; a first comparator to compare an output of said integrator with a second fixed reference level signal and to provide an output responsive to said comparison for regulating said SMPS output voltage.
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Citations
21 Claims
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1. A switch mode power supply (SMPS) controller for regulating the output voltage of an SMPS in response to a feedback signal from a winding of a magnetic energy storage device forming part of an output circuit of the SMPS, the SMPS controller comprising:
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a reference level input to receive an output reference level signal; an input to receive said feedback signal, said feedback signal being responsive to a voltage on said winding of said magnetic energy storage device; an integrator to integrate a difference between said feedback signal and a first fixed reference level signal; a first comparator to compare an output of said integrator with a second fixed reference level signal and to provide an output responsive to said comparison for regulating said SMPS output voltage; a second comparator to compare a signal derived from said feedback signal with a third reference level signal derived from said output reference level signal, at a time when said first comparator indicates that said integrator output is substantially equal to said second fixed reference level signal; and a controller output coupled to an output of said second comparator to provide a regulation signal for controlling said SMPS to regulate said SMPS output voltage. - View Dependent Claims (2, 3, 6, 7, 8, 9, 10, 11)
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4. A switch mode power supply (SMPS) controller for regulating the output voltage of an SMPS in response to a feedback signal from a winding of a magnetic energy storage device forming part of an output circuit of the SMPS, the SMPS controller comprising:
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a reference level input to receive an output reference level signal; an input to receive said feedback signal, said feedback signal being responsive to a voltage on said winding of said magnetic energy storage device; an integrator to integrate a difference between said feedback signal and a first fixed reference level signal; a first comparator to compare an output of said integrator with a second fixed reference level signal and to provide an output responsive to said comparison for regulating said SMPS output voltage; and a second integrator, responsive to said output from said first comparator to begin integrating a waveform of said feedback signal, and having an output to provide a signal responsive to a value of said feedback signal at a point of approximately zero flux in said magnetic energy storage device. - View Dependent Claims (5, 20, 21)
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12. A method of regulating the output voltage of an SMPS in response to a feedback signal from a winding of a magnetic energy storage device forming part of an output circuit of the SMPS, the method comprising:
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receiving an output reference level signal; receiving a feedback signal, said feedback signal being responsive to a voltage on said magnetic energy storage device winding; integrating a difference between said feedback signal and a first fixed reference level signal; comparing an output of said integration with a second fixed reference level signal and providing an output responsive to said comparison; regulating said SMPS using said output of said comparing; comparing a signal derived from said feedback signal with a third reference level signal derived from said output reference level signal at a time when said comparing of said integration output and said second fixed reference level signal indicates that said integrator output is substantially equal to said second fixed reference level signal; and regulating said SMPS output voltage responsive to said comparing of said signals derived from said feedback signal and said third reference level signal. - View Dependent Claims (13)
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14. A method of regulating the output voltage of an SMPS in response to a feedback signal from a winding of a magnetic energy storage device forming part of an output circuit of the SMPS, the method comprising:
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receiving an output reference level signal; receiving a feedback signal, said feedback signal being responsive to a voltage on said magnetic energy storage device winding; integrating a difference between said feedback signal and a first fixed reference level signal; comparing an output of said integration with a second fixed reference level signal and providing an output responsive to said comparison; regulating said SMPS using said output of said comparing; integrating a waveform of said feedback signal beginning at a time determined by said output of said comparing; and regulating said SMPS using an output of said waveform integrating.
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15. A method of regulating the output voltage of an SMPS in response to a feedback signal from a winding of a magnetic energy storage device forming part of an output circuit of the SMPS, the method comprising:
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receiving an output reference level signal; receiving a feedback signal, said feedback signal being responsive to a voltage on said magnetic energy storage device winding; integrating a difference between said feedback signal and a first fixed reference level signal;
wherein said integrating comprises integrating beginning at a time when a switching device controlling switching of power to said magnetic energy storage device switches on;comparing an output of said integration with a second fixed reference level signal and providing an output responsive to said comparison; and regulating said SMPS using said output of said comparing.
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16. A method of regulating the output of an SMPS operating in a discontinuous conduction mode, the SMPS including a magnetic energy storage device having at least one winding, the method comprising:
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integrating a feedback signal from said at least one winding of said SMPS from a first point in time of known, substantially zero magnetic flux in said magnetic energy storage device to determine a second time at which said magnetic flux is again substantially zero; and determining an error signal by integrating a waveform of said feedback signal from said second time to a third later time; and using said error signal to regulate said SMPS. - View Dependent Claims (17, 18)
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19. An SMPS controller for regulating the output of an SMPS operating in a discontinuous conduction mode, the SMPS including a magnetic energy storage device having at least one winding, the SMPS controller comprising:
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a first integrator to integrate a feedback signal from said at least one winding of said SMPS from a first point in time of known, substantially zero magnetic flux in said magnetic energy storage device to determine a second time at which said magnetic flux is again substantially zero; and a second integrator to integrate a waveform of said feedback signal from said second time to a third later time and to output an error signal for controlling said SMPS.
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Specification