| Patent application number | Description | Published |
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| 20100202175 | 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 a feedback current signal that corresponds to a peak switching current in response to a sense signal from a power supply regulator output. A comparator is coupled to compare the feedback current signal with a reference voltage. A modulation circuit is coupled to the feedback circuit to generate a pulse width modulated switching signal with fixed switching frequency in response to the feedback current signal and the reference voltage. 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 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. | 08-12-2010 |
| 20100246222 | METHOD AND APPARATUS FOR DIGITAL CONTROL OF A SWITCHING REGULATOR - Various techniques directed to the digital control of a switching regulator are disclosed. In one aspect, a power supply regulator includes a compare circuit to be coupled to receive a feedback signal representative of an output level of a power supply. This causes a feedback state signal to be generated having a first feedback state that represents an output level of the power supply that is above a threshold level and a second feedback state that represents an output level of the power supply that is below the threshold level. An adjustment circuit is coupled to the compare circuit to adjust the feedback state signal in response to at least one of adjusting the threshold level or adjusting the feedback signal. The adjustment to the feedback state signal tends to cause the feedback state signal to revert from a state at the time of adjustment to a state immediately preceding the adjustment. A control circuit is to be coupled to a power switch and is to be coupled to receive an oscillating signal and the feedback state signal. The control circuit is to control switching of the power switch in response to the oscillating signal and the feedback state signal to regulate the output level of the power supply. | 09-30-2010 |
| 20110019441 | METHOD AND APPARATUS FOR DIGITAL CONTROL OF A SWITCHING REGULATOR - In one aspect, a power supply regulator includes a feedback terminal, a node, a control circuit, a first current source, and a second current source. The node is coupled to the feedback terminal to provide a feedback state signal in response to a feedback current through the feedback terminal. The feedback state signal has feedback states that represent an output of the power supply. The control circuit is to be coupled to a power switch and to receive the feedback state signal to regulate the output of the power supply. The first current source is coupled to the node to provide a first current to the node. The second current source is coupled to the node to selectively remove a second current from the node to modulate the feedback current and to alter the feedback state of the feedback state signal. | 01-27-2011 |
| 20110089761 | 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. | 04-21-2011 |
| 20110157943 | 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. | 06-30-2011 |
| 20110211373 | 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 duty cycle of a pulse width modulated switching signal to provide a fixed peak switching current in the switch during light load conditions and a variable peak switching current during load conditions other than the light load condition. The multi-cycle modulator circuit enables the switch signal generator to provide a switch signal uninterrupted if the load condition is other than the light load condition 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 load condition is the light load condition. The multi-cycle modulator circuit adjusts the first time period in response to the feedback signal to regulate the output. | 09-01-2011 |
| 20110267846 | APPARATUS AND METHOD FOR SENSING OF ISOLATED OUTPUT - A controller for use in a power converter providing sensing of an isolated output is disclosed. An example controller includes a current controller to be coupled to an energy transfer element and an input of the power converter. A control circuit is included that generates a mode select signal coupled to be received by the current controller. A first, second or third current is enabled in the current controller in response to a selection of a first, second or third mode of operation, respectively, of the current controller by the control circuit. The first current is substantially zero, the second current is greater than the third current and the third current is greater than the first current. A first feedback circuit is coupled to the control circuit and is coupled to generate a first feedback signal representative of an output of the power converter during the first mode of operation after a period of operation of the second mode of operation of the current controller. A second feedback circuit is coupled to the control circuit and is coupled to generate a second feedback signal representative of the output of the power converter during the first mode of operation after a period of operation of the third mode of operation of the current controller. The control circuit is coupled to control selections of the first, second or third modes of operation in response to the first and second feedback signals to control a transfer of energy from the input of the power converter to the output of the power converter. | 11-03-2011 |
| 20110267847 | APPARATUS AND METHOD FOR DETECTING A CHANGE IN OUTPUT VOLTAGE OF AN ISOLATED POWER CONVERTER - A controller for use in a power converter to detect changes in output voltage. An example controller includes a drive circuit to generate a switching signal. The switching signal is coupled to be received by a power switch to be coupled to an energy transfer element and an input of the power converter to control a transfer of energy from the input of the power converter to an output of the power converter. An output voltage sensor is coupled to the drive circuit and coupled to receive a feedback signal representative of the output of the power converter. The output voltage sensor includes first and second pulse sampler circuits. The first pulse sampler circuit is coupled to capture a first peak voltage representative of a second peak of a ringing voltage of the feedback signal at a first time in the feedback signal. The second pulse sampler circuit is coupled to capture a second peak voltage representative of the second peak of the ringing voltage of the feedback signal at a second time in the feedback signal. The output voltage sensor is coupled to output a change signal to the drive circuit in response to the first and second peak voltages. | 11-03-2011 |
