Patent application number | Description | Published |
20090103337 | METHOD AND APPARATUS TO REDUCE THE VOLUME REQUIRED FOR BULK CAPACITANCE IN A POWER SUPPLY - A driver circuit included in a power supply having a rectifier coupled to a single phase AC input voltage is disclosed. An example driver circuit includes a drive signal generator to generate a drive signal to be coupled to a variable impedance element. A voltage sensor is coupled to the drive signal generator and is to be coupled to sense a voltage across a high voltage capacitance. The driver circuit is to be coupled to control the variable impedance element in response to the voltage sensor. A low voltage capacitance is allowed to receive current from the input if the sensed voltage is less than a second threshold value. The low voltage capacitance is prevented from receiving current from the input if the sensed voltage is greater than a first threshold value. | 04-23-2009 |
20090140710 | METHOD AND APPARATUS FOR A HIGH VOLTAGE POWER SUPPLY CIRCUIT - A high voltage power supply method and apparatus is disclosed. An example power supply circuit includes a rectifier circuit coupled to receive an AC input voltage. A switchmode power converter circuit is coupled to the rectifier circuit to receive a rectified input voltage to generate a regulated output voltage. A switch is coupled between the rectifier circuit and the switchmode power converter circuit. A sense circuit is coupled to detect the AC input voltage. The sense circuit is coupled to turn off the switch when an absolute value of the AC input voltage exceeds a first threshold value. The sense circuit is coupled to turn on the switch when the absolute value of the AC input voltage is below a second threshold value. | 06-04-2009 |
20090153285 | METHOD AND APPARATUS FOR TRANSFERRING ENERGY IN A POWER CONVERTER CIRCUIT - A reduced cost energy transfer element for power converter circuits. In one embodiment, an energy transfer element according to an embodiment of the present invention includes a magnetic element having an external surface with at least a first winding and a second winding wound around the external surface of the magnetic element without a bobbin. As such, energy to be received from a power converter circuit input is to be transferred from the first winding to the second winding through a magnetic coupling provided by the magnetic element to a power converter circuit output. | 06-18-2009 |
20090212755 | METHOD AND APPARATUS TO PROVIDE TEMPORARY PEAK POWER FROM A SWITCHING REGULATOR - Various techniques directed to providing temporary peak power from a switching regulator are disclosed. In one aspect, a switching regulator includes a switch that is to be coupled between a power supply input and an energy transfer element of the power supply. A controller is coupled to be responsive to a feedback signal to be received from an output of the power supply. The controller is coupled to switch the switch in response to the feedback signal to regulate the output of the power supply. An oscillator is coupled to provide an oscillating signal to the controller to determine a maximum switching frequency of the switch. The oscillating signal is coupled to oscillate at a first frequency under a first moderate load condition at the power supply output. The oscillating signal is coupled to oscillate at a second frequency under a second peak load condition at the power supply output. | 08-27-2009 |
20090295346 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE IN A POWER CONVERTER - A control circuit for use in a power converter with an unregulated dormant mode of operation is disclosed. In one aspect a power converter includes a drive signal generator coupled to generate a drive signal to control switching of a power switch to be coupled to the control circuit to regulate a flow of energy to a power converter output in response to an energy requirement of one or more loads to be coupled to the power converter output. An unregulated dormant mode control circuit is included and is coupled to render dormant the drive signal generator thereby ceasing the regulation of the flow of energy to the power converter output by the drive signal generator when the energy requirement of the one or more loads falls below a threshold. The drive signal generator is coupled to be unresponsive to changes in the energy requirements of the one or more loads when dormant. The unregulated dormant mode control circuit is coupled to power up the drive signal generator after a period of time has elapsed. The drive signal generator is coupled to again be responsive to changes in the energy requirement of the one or more loads after the period of time has elapsed. | 12-03-2009 |
20100033147 | METHOD AND APPARATUS FOR MAINTAINING A CONSTANT LOAD CURRENT WITH LINE VOLTAGE IN A SWITCH MODE POWER SUPPLY - A power supply regulator including a variable current limit threshold that increases during an on time of a switch. In one aspect, a power supply regulator includes a comparator that has a first input coupled to sense a voltage representative of a current flowing through a switch during an on time of the switch. The comparator has a second input coupled to receive a variable current limit threshold that increases during the on time of the switch. A feedback circuit is coupled to receive a feedback signal representative of an output voltage at an output of a power supply. A control circuit is coupled to generate a control signal in response to an output of the comparator and in response to an output of the feedback circuit. The control signal is to be coupled to a control terminal of the switch to control switching of the switch. | 02-11-2010 |
20100254166 | METHOD AND APPARATUS FOR ON/OFF CONTROL OF A POWER CONVERTER - A power converter control method and apparatus is disclosed. An example power converter controller according to aspects of the present invention includes a feedback sampling circuit coupled to receive a feedback signal representative of an output of a power converter to generate feedback signal samples during enabled switching cycles. The power converter controller also includes a switch conduction control circuit coupled to the feedback sampling circuit. The switch conduction control circuit includes switch conduction enable circuitry coupled to enable or disable the conduction of a power switch during a switching cycle in response to the feedback signal samples. The switch conduction control circuit also includes switch conduction scheduling circuitry coupled to determine a varying number of future enabled and disabled switching cycles in response to the feedback signal samples from a present switching cycle and one or more past switching cycles. | 10-07-2010 |
20100259953 | METHOD AND APPARATUS FOR LIMITING MAXIMUM OUTPUT POWER OF A POWER CONVERTER - An example power converter includes a power switch, a controller, and a current offset circuit. The controller is coupled to switch the power switch between an ON state and an OFF state to regulate an output of the power converter. The controller is adapted to terminate the ON state of the power switch in response to a switch current flowing through the power switch reaching a switch current threshold. The current offset circuit is coupled to generate an offset current in response to an input voltage of the power converter and an input current of the power converter is adjusted in response to the offset current. | 10-14-2010 |
20100321039 | METHOD AND APPARATUS TO SELECT A PARAMETER/MODE BASED ON A TIME MEASUREMENT - An example integrated control circuit includes a regulator, a first comparator, a second comparator, and a counter. The regulator is to charge, during a time period, a capacitor. The first comparator is to provide an output indicating when a voltage on the capacitor reaches a first threshold voltage. The second comparator is coupled to provide an output indicating when the voltage on the capacitor reaches a second threshold voltage. The counter is coupled to begin counting in response to the first threshold voltage being reached and is coupled to stop counting in response to the second threshold voltage being reached. The counter is coupled to provide an output representative of the capacitance value of the capacitor during the time period and the integrated control circuit receives a bias current at the terminal from the capacitor to provide power to operate the integrated control circuit after the time period has ended. | 12-23-2010 |
20110025278 | METHOD AND APPARATUS FOR IMPLEMENTING A POWER CONVERTER INPUT TERMINAL VOLTAGE DISCHARGE CIRCUIT - A circuit to discharge a capacitance between input terminals of a power system is disclosed. An example circuit includes a control circuit coupled to an input of a power system. The control circuit is coupled to detect whether an electrical energy source is coupled to an input of the power system. A switch is also included and is coupled to the control circuit and to the input of the power system. The control circuit is coupled to drive the switch in a first operating mode when the electrical energy source is coupled to the input of the power system. The control circuit is coupled to drive the switch in a second operating mode when the electrical energy source is uncoupled from the input of the power system. A capacitance coupled between input terminals of the input of the power system is discharged through the switch to a threshold voltage in less than a maximum period of time from when the electrical power source is uncoupled from the input terminals of the power system. | 02-03-2011 |
20110025288 | METHOD AND APPARATUS FOR MAINTAINING A CONSTANT LOAD CURRENT WITH LINE VOLTAGE IN A SWITCH MODE POWER SUPPLY - A power supply regulator including a variable current limit threshold that increases during an on time of a switch. In one aspect, a power supply regulator includes a comparator coupled to receive a signal representative of a current through a switch during an on time of the switch. The comparator is further coupled to receive a variable current limit threshold that increases during the on time of the switch. The power supply regulator also includes a feedback circuit coupled to receive a feedback signal representative of an output of a power supply. A control circuit is also included and is coupled to the switch, to an output of the comparator, and to an output of the feedback circuit. The control circuit is coupled to control a switching of the switch in response the output of the comparator and the output of the feedback circuit to regulate the output of the power supply. | 02-03-2011 |
20110085358 | METHOD AND APPARATUS FOR HIGH-SIDE INPUT WINDING REGULATION - A power supply control circuit for use in a power supply is disclosed. An example power supply control circuit includes a power switch coupled between first and second terminals. The first terminal is to be coupled to a positive input supply rail of the power supply. The second terminal is to be coupled to an energy transfer element input of the power supply. A sampling circuit is coupled to a third terminal. The sampling circuit coupled to sample a signal across the energy transfer element input of the power supply during an off time of the power switch to provide a sampled output of the power supply. The sampled output of the power supply is disabled from being be resampled by the sampling circuit during an on time of the power switch. A control circuit coupled to the sampling circuit and the power switch, the control circuit coupled to switch the power switch in response to the sampled output of the power supply. | 04-14-2011 |
20110149615 | METHOD AND APPARATUS FOR LIMITING MAXIMUM OUTPUT POWER OF A POWER CONVERTER - An example power converter includes an energy transfer element, a switch, a controller, and a current offset circuit. The controller is coupled to switch the switch between an ON state and an OFF state to regulate the output of the power converter. The controller is also adapted to terminate the ON state of the switch in response to a switch current flowing through the switch reaching a switch current threshold. An auxiliary winding of the energy transfer element is adapted to generate an auxiliary winding voltage that is representative of an input voltage of the power converter only during the ON state of the switch. The current offset circuit is coupled to the auxiliary winding to generate an offset current to flow through the switch in response to the auxiliary winding voltage, where an input current of the power converter is adjusted in response to the offset current. | 06-23-2011 |
20110156675 | POWER CONVERTER HAVING A SWITCH COUPLED BETWEEN WINDINGS - An example power converter includes a first winding, a second winding, a switch, a controller and an output circuit. The second winding is magnetically coupled to the first winding and the controller includes a feedback terminal and a common terminal. The controller is coupled to control the switch to regulate an output of the power converter in response to a feedback voltage received at the feedback terminal. The output circuit is coupled between the common terminal of the controller and a common reference of the power converter to provide an output voltage to a load. The feedback voltage is a positive voltage with respect to the common terminal and the output voltage is a negative voltage with respect to the common reference of the power converter. | 06-30-2011 |
20110156689 | POWER CONVERTER HAVING A SWITCH COUPLED BETWEEN WINDINGS - An example power converter includes a first winding, a second winding, a switch, and a controller. The second winding is magnetically coupled to the first winding and the switch is coupled between the first winding and the second winding such that a current flows through the first winding, the second winding and the switch when the switch is in an ON state. The controller is coupled to control the switch to regulate an output of the power converter in response to a feedback signal. | 06-30-2011 |
20110194309 | METHOD AND APPARATUS TO CONTROL A POWER CONVERTER HAVING A LOW LOOP BANDWIDTH - A power converter controller is disclosed. An example power converter controller includes a feedback sensor circuit coupled to receive a feedback signal representative of an output of the power converter. The controller also includes a feedback sampling signal generator coupled to generate a feedback sampling signal coupled to be received by the feedback sensor circuit. The feedback sensor circuit is coupled to sample the feedback signal in response to the feedback sampling signal. The controller also includes a state machine coupled to the feedback sensor circuit to control switching of a switch of the power converter circuit according to one of a plurality of operating condition states in response to the feedback sensor circuit. The controller also includes a feedback time period signal generator coupled to generate a feedback time period signal coupled to be received by the state machine. A period of a feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is coupled to be updated in response to the feedback time period signal. | 08-11-2011 |
20110194315 | Power supply circuit with a control terminal for different functional modes of operation - A method of operation for flyback power converter includes operating a controller of the flyback power converter in a regulation mode when a control signal is below a first threshold. The control signal is provided as an input to a terminal of the flyback power converter. When the control signal is below a second threshold and above the first threshold, the controller is operated in a limiting mode. The controller is operated in an external command mode when the control signal is below a third threshold and above the second threshold. Lastly, when the control signal is above the third threshold, the controller is operated in a protection mode. | 08-11-2011 |
20110199798 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE IN A POWER CONVERTER - A control circuit for use in a power converter with an unregulated dormant mode of operation is disclosed. In one aspect a power converter includes a drive signal generator that is coupled to generate a drive signal to control switching of a power switch coupled to the control circuit to regulate a flow of energy to an output of the power converter in response to an energy requirement of one or more loads coupled to the output of the power converter. A regulator circuit is coupled to charge a capacitor. The capacitor determines a time period. The regulator circuit is coupled to not charge the capacitor if the energy requirement of the one or more loads coupled to the output of the power converter falls below a threshold. The regulator is coupled to again charge the capacitor after the time period has elapsed. An unregulated dormant mode control circuit is coupled to render dormant the drive signal generator and the regulator circuit during the time period thereby causing regulation of the flow of energy to the output of power converter output to cease. The unregulated dormant mode control circuit is further coupled to power up the drive signal generator and the regulator after the time period has elapsed. | 08-18-2011 |
20110285374 | METHOD AND APPARATUS FOR MAINTAINING A CONSTANT LOAD CURRENT WITH LINE VOLTAGE IN A SWITCH MODE POWER SUPPLY - A method and apparatus of reducing peak current variation with changing input line voltage in a switch mode power supply is disclosed. An example method includes sensing a current through a switching device of the switch mode power supply. A variable current limit threshold is generated, which increases from a first level to a second level during an on time of the switching device. The current is compared to the variable current limit threshold. A feedback signal representative of an output voltage of the switch mode power supply is sensed. The switching device is controlled in response to the feedback signal and said comparing the current to the variable current limit threshold. | 11-24-2011 |
20120002448 | METHOD AND APPARATUS FOR ON/OFF CONTROL OF A POWER CONVERTER - A power converter is disclosed. An example power converter includes an energy transfer element coupled between a power converter input and a power converter output. A power switch is coupled to the energy transfer element and the power converter input. A feedback sampling circuit is coupled to receive a feedback signal representative of the power converter output to generate feedback signal samples during switching cycles. A switch conduction scheduling circuit is coupled to determine enabling and disabling of the power switch in future switching cycles in response to the feedback signal samples from a present switching cycle and one or more past switching cycles. A switch conduction control circuit is coupled to enable or disable conduction of the power switch during a switching cycle to control an amount of energy transferred from the power converter input to the power converter output. | 01-05-2012 |
20120026759 | ULTRA LOW STANDBY CONSUMPTION IN A HIGH POWER POWER CONVERTER - A power converter with low power consumption during a standby operating condition. An example power controller includes a main converter coupled to a dc input of the power converter to control a transfer of energy from the dc input of the power converter to a main output of the power converter. A standby converter is also included and is coupled to the dc input of the power converter to control a transfer of energy from the dc input of the power converter to a standby output of the power converter during a standby operating condition of the power converter. A standby circuit is also included and is coupled to the dc input of the power converter and coupled to the main converter. The standby circuit decouples the main converter from the dc input of the power converter during the standby operating condition of the power converter. | 02-02-2012 |
20120081931 | METHOD AND APPARATUS TO CONTROL A POWER CONVERTER HAVING A LOW LOOP BANDWIDTH - An example controller includes a feedback sensor circuit that receives a feedback signal representative of an output of a power converter. A feedback sampling signal generator is coupled to generate a feedback sampling signal. The feedback sensor circuit samples the feedback signal in response to the feedback sampling signal. A state machine controls switching of a switch of a power converter circuit according to one of a plurality of operating condition states in response to the feedback sensor circuit. Each of the plurality of operating condition states includes a substantially fixed switch on time. A feedback time period signal generator generates a feedback time period signal received by the state machine. A period of the feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is updated in response to the feedback time period signal. | 04-05-2012 |
20120087156 | METHOD AND APPARATUS FOR LIMITING MAXIMUM OUTPUT POWER OF A POWER CONVERTER - An example power converter includes an energy transfer element, a switch, a controller, and a current offset circuit. The controller switches the switch between an ON state and an OFF state to regulate the output of the power converter and is adapted to terminate the ON state of the switch in response to a switch current flowing through the switch reaching a switch current threshold. The current offset circuit is coupled to the input to be directly powered from an input voltage of the power supply. The current offset circuit generates an offset current to flow through the switch only during the ON state of the switch in response to a magnitude of the input voltage. The input current of the power converter is adjusted in response to the offset current. | 04-12-2012 |
20120105018 | METHOD AND APPARATUS FOR IMPLEMENTING A POWER CONVERTER INPUT TERMINAL VOLTAGE DISCHARGE CIRCUIT - A switch is coupled to a control circuit and to an input of a power converter. The control circuit is coupled to drive the switch in a first operating mode to transfer energy from the input to an output of the power converter when an electrical energy source is coupled to the input of the power converter. The control circuit is coupled to drive the switch in a second operating mode when the electrical energy source is uncoupled from the input. A capacitance is coupled between input terminals of the input of the power converter and is discharged to a threshold voltage in less than a maximum period of time from when the electrical energy source is uncoupled from the input terminals. The control circuit is coupled to drive the switch to have a high average impedance in the first operating mode. | 05-03-2012 |
20120139342 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH OUTPUT RESET IN A POWER CONVERTER - An implementation of an unregulated dormant mode with an output reset controller in a power converter is disclosed. An example method for controlling an output of a power converter includes generating a drive signal with a drive signal generator to regulate a flow of energy to one or more loads coupled to an output of the power converter in response to an energy requirement of the one or more loads. The drive signal generator is rendered dormant to cease for a first time period the regulation of energy flow to the one or more loads when the energy requirement of the one or more loads falls below a threshold value. The energy requirement of the one or more loads is not responded to during the first time period. The drive signal generator is then powered up to resume after the first time period has elapsed the regulation of energy flow to the one or more loads. After the first time period has elapsed, it is identified whether there is an increase in the energy requirement of the one or more loads. If there is the increase in the energy requirement of the one or more loads, the output of the power converter is reset to allow a voltage at the output of power converter to be discharged during a second time period after the first time period has elapsed to a value substantially below a normal regulation output voltage. | 06-07-2012 |
20120170329 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE IN A POWER CONVERTER - A control circuit includes a drive signal generator controlling switching of a power switch to regulate a flow of energy to one or more loads coupled to a power converter output. A regulator circuit charges a capacitor to a first voltage and stops charging the capacitor if an energy requirement of the one or more loads falls below a threshold. The regulator again charges the capacitor after the capacitor is discharged from the first voltage to a second voltage. An unregulated dormant mode control circuit renders dormant the drive signal generator and the regulator circuit while the capacitor is discharged from the first voltage to the second voltage causing the regulation of the flow of energy to the power converter output to cease. The drive signal generator and the regulator circuit are powered up after the capacitor is discharged from the first voltage to the second voltage. | 07-05-2012 |
20120243266 | METHOD AND APPARATUS FOR HIGH-SIDE INPUT WINDING REGULATION - A controller for use in a power converter includes a control circuit coupled to control switching of a power switch coupled between a positive input supply rail of the power converter and an energy transfer element input of the power converter. A sampling circuit is coupled to the control circuit and is coupled to receive a signal across the energy transfer element input during an off time of the power switch to provide a sampled output of the converter. The sampled output of the power converter is disabled from being resampled by the sampling circuit during an on time of the power switch. A switch conduction scheduling circuit is included in the control circuit and is coupled to the sampling circuit such that the control circuit is coupled to switch the power switch in response to the sampled output of the power converter. | 09-27-2012 |