Patent application number | Description | Published |
20090073733 | METHOD AND APPARATUS TO REDUCE AUDIO FREQUENCIES IN A SWITCHING POWER SUPPLY - A controller for use in a power supply regulator is disclosed. One controller includes a feedback circuit coupled to generate an equivalent switching frequency signal in response to a sense signal from a power supply regulator output. A comparator is coupled to compare the equivalent switching frequency signal with a reference signal. A period modulation circuit is coupled to the feedback circuit to generate a period modulation switching signal in response to the equivalent switching frequency signal. A multi-cycle modulator circuit is coupled to the output of the comparator. The multi-cycle modulator circuit is coupled to enable or disable a switch signal from the controller, which is to be coupled to a switch of the power supply regulator. A group of two or more consecutive switching cycles is separated from a next group having two or more switching cycles by a time of no switching. The time of no switching is adjusted in closed loop to regulate a transfer of energy from a power supply regulator input to the power supply regulator output. | 03-19-2009 |
20090201701 | COMPENSATION FOR PARAMETER VARIATIONS IN A FEEDBACK CIRCUIT - Techniques to compensate for parameter variations in a feedback circuit are disclosed. In one embodiment, a regulator circuit includes an energy source coupled to output a generated current in response to a control current. A feedback resistor is coupled to an output of the regulator circuit. The feedback resistor is coupled to conduct a feedback current responsive to the output of the regulator circuit. A current amplifier is coupled to the feedback resistor to generate the control current in response to the feedback current. A compensation network is coupled to the current amplifier to adjust the control current in response to an extrinsic parameter of the regulator circuit. The compensation network includes a transistor and first, second and third resistors. The first resistor is coupled between the feedback resistor and a collector of the transistor. The second resistor coupled between the collector and the base of the transistor. The third resistor coupled between the base and an emitter of the transistor. | 08-13-2009 |
20090251116 | METHOD AND APPARATUS FOR POWER CONVERSION AND REGULATION - Techniques are disclosed to control a power converter with multiple output voltages. One example regulated power converter includes a an energy transfer element coupled between a power converter input and first and second power converter outputs. A switch is coupled between the power converter input and the energy transfer element such that switching of the switch causes a first output voltage to be generated at the first power converter output and a second output voltage to be generated at the second power converter output. A current in the energy transfer element is coupled to increase when a voltage across the energy transfer element is a difference between an input voltage at the power converter input and the first output voltage. The current in the energy transfer element is coupled to decrease when the voltage across the energy transfer element is a sum of the first and second output voltages. | 10-08-2009 |
20100067270 | METHOD AND APPARATUS TO REDUCE LINE CURRENT HARMONICS FROM A POWER SUPPLY - A method and apparatus for controlling a power converter. In one aspect, a controller for use in a power converter includes a first calculator coupled to determine an end of an on time of a power switch of the power converter by integrating an input current to output an on time signal representative of the end of the on time of the power switch. The controller also includes a second calculator coupled to determine an end of an off time of the power switch by integrating a difference between an input voltage and an output voltage to output an off time signal representative of the end of the off time of the power switch. | 03-18-2010 |
20110018343 | METHOD AND APPARATUS FOR REGULATING AN ADDITIONAL OUTPUT OF A POWER CONVERTER - An example post regulator controller for use in a power converter having a regulated output and an additional output is disclosed. The post regulator controller includes an inductor to be coupled between the regulated output of the power converter and a post regulator switch of the power converter. The inductor is to be coupled to drive the post regulator switch with an induced voltage across the inductor to redirect energy from the regulated output to the additional output of the power converter. | 01-27-2011 |
20120218788 | METHOD AND APPARATUS FOR DIGITAL CONTROL OF A SWITCHING REGULATOR - In one aspect, a power supply includes an energy transfer element, a switch, a feedback circuit, a comparator, a state machine, and a control circuit. The feedback circuit generates a feedback signal representative of an output level of the power supply. The comparator provides a feedback state signal having a first feedback state that represents the output level of the power supply being above a threshold level and a second feedback state that represents the output level being below the threshold level. The state machine selectively modulates a first signal in response to the feedback state signal, where the first signal is the feedback signal or the threshold value signal. The control circuit is coupled to control switching of the switch to regulate the output level of the power supply in response to the feedback state signal. | 08-30-2012 |
20120224399 | METHOD AND APPARATUS TO REDUCE AUDIO FREQUENCIES IN A SWITCHING POWER SUPPLY - An example controller for use in a power supply regulator includes a switch signal generator, a modulation circuit, and a multi-cycle modulator circuit. The modulation circuit modulates the period of a modulation switching signal when an equivalent switching frequency is greater than a reference frequency and fixes the switching period when the equivalent switching frequency is less than the reference frequency. The multi-cycle modulator circuit enables the switch signal generator to provide a switch signal uninterrupted if the equivalent switching frequency is greater than the reference frequency and disables the switch signal generator for a first time period and then enables the switch signal generator for a second time period when the equivalent frequency is less than the reference frequency. The multi-cycle modulator circuit varies the first time period to regulate the output. | 09-06-2012 |
20120243277 | METHOD AND APPARATUS TO REDUCE LINE CURRENT HARMONICS FROM A POWER SUPPLY - In one aspect, a power converter includes a power switch, an energy storage element, a driver, a first calculator, and a second calculator. The first calculator coupled to determine an end of an on time of a power switch of the power converter by integrating an input current to output an on time signal representative of the end of the on time of the power switch. The second calculator coupled to determine an end of an off time of the power switch by integrating a difference between an input voltage and an output voltage to output an off time signal representative of the end of the off time of the power switch. The driver controls the power switch such that an input current of the power converter is substantially proportional to an input voltage of the power converter in response to the on time signal and the off time signal. | 09-27-2012 |