Patent application number | Description | Published |
20080304187 | FAULT CONDITION PROTECTION - A power converter controller circuit is disclosed. In one aspect, a power converter controller circuit includes a control circuit to generate a switching signal to be coupled to a power switch to control power delivered to an output of a power converter. A timing circuit is to be coupled to the power switch and coupled to receive a feedback signal and the switching signal. The timing circuit is to disable the power switch from receiving the switching signal in response to the feedback signal after detection of a fault condition. The feedback signal repeatedly transitions between first and second states in response to the output when the power supply operates normally. The feedback signal maintains its state when the power supply is in the fault condition. The feedback signal transitions between the first and second states independently from the switching signal. | 12-11-2008 |
20100194198 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH AN EVENT COUNTER IN A POWER CONVERTER - A control circuit for use in a power converter with an unregulated dormant mode of operation 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 for more than a first period of time. 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 second 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. | 08-05-2010 |
20100194367 | METHOD AND APPARATUS TO REGULATE AN OUTPUT VOLTAGE OF A POWER CONVERTER AT LIGHT/NO LOAD CONDITIONS - An example apparatus to regulate an output voltage of a power converter at light/no load conditions includes a driver circuit, a feedback circuit, and an adjustable voltage reference circuit. The driver circuit is coupled to output a drive signal to switch a power switch between an ON state and an OFF state to regulate an output of the power converter. The feedback circuit is coupled to the driver circuit and is further coupled to output an enable signal to switch the power switch to an ON state in response to an output voltage signal. The adjustable voltage reference circuit is coupled to adjust a voltage reference such that a bias winding voltage of the power converter is adjusted nonlinearly in response to a load that is to be coupled to the output of the power converter. | 08-05-2010 |
20100194445 | POWER SUPPLY CONTROLLER WITH INPUT VOLTAGE COMPENSATION FOR EFFICIENCY AND MAXIMUM POWER OUTPUT - A controller for a power supply includes a logic block and a time-to-frequency converter. The logic block is to generate a drive signal in response to a clock signal. The drive signal is to be coupled to control switching of a power switch of the power supply to regulate an output of the power supply. The time-to-frequency converter is coupled to the logic block and generates the clock signal having a frequency responsive to a time period of the drive signal. | 08-05-2010 |
20100277838 | FAULT CONDITION PROTECTION - A regulator for a switched mode power supply includes switching regulator logic, a counter and a logic gate. The switching regulator logic is coupled to receive a feedback signal and to generate a switching signal in response. The feedback signal periodically cycles between a first state and a second state when the power supply operates normally. The counter is coupled to receive the feedback signal and an output of the counter indicates an auto-restart mode of the regulator in response to the feedback signal remaining in the first state for a predetermined count. An output of the logic gate enables the power switch to turn on and off in response to the switching signal when the output of the counter does not indicate the auto-restart mode and the output of the logic gate disables the power switch in response to the output of the counter indicating the auto-restart mode. | 11-04-2010 |
20110080209 | METHOD AND APPARATUS FOR IMPLEMENTING SLEW RATE CONTROL USING BYPASS CAPACITOR - A circuit to control the slew rate of charging a capacitance using the capacitance is disclosed. An example circuit includes a regulator circuit to regulate a supply voltage during a normal operation mode of the circuit. A capacitance circuit is coupled to the regulator circuit. The regulator circuit is coupled to charge a capacitance between a first node and a second node of the capacitance circuit with a charge current. A slew rate control circuit is coupled to the regulator circuit and the capacitance circuit. The slew rate control circuit sets a slew rate of a voltage between the first and second nodes during a power up mode of the circuit. | 04-07-2011 |
20110121889 | Temperature independent reference circuit - A temperature independent reference circuit includes first and second bipolar transistors with commonly coupled bases. First and second resistors are coupled in series between the emitter of the second bipolar transistor and ground. The first and second resistors have first and second resistance values, R | 05-26-2011 |
20110188274 | FAULT CONDITION PROTECTION - A regulator for a switched mode power supply includes switching regulator logic, a counter and a switching transistor. The switching regulator logic is coupled to receive a feedback signal and to generate a switching signal in response. The feedback signal periodically cycles between a first state and a second state when the power supply operates normally. The counter is coupled to receive the feedback signal and an output of the counter indicates an auto-restart mode of the regulator in response to the feedback signal remaining in the first state for a predetermined count. The switching transistor is turned on and off in response to the switching signal when the output of the counter does not indicate the auto-restart mode and is disabled when the output of the counter indicates the auto-restart mode. | 08-04-2011 |
20110255310 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH AN EVENT COUNTER IN A POWER CONVERTER - A method for controlling an output of a power converter includes generating a drive signal with a control circuit, entering a dormant mode of operation that includes powering down the control circuit if a flow of energy to an output of the power converter is less than a threshold value for more than a first period of time, and powering up the control circuit after it is in the dormant mode of operation for a second period of time. | 10-20-2011 |
20110298529 | Temperature independent reference circuit - A temperature independent reference circuit includes first and second bipolar transistors with commonly coupled bases. First and second resistors are coupled in series between the emitter of the second bipolar transistor and ground. The first and second resistors have first and second resistance values, R | 12-08-2011 |
20120068680 | METHOD AND APPARATUS FOR IMPLEMENTING SLEW RATE CONTROL USING BYPASS CAPACITOR - An example circuit includes a regulator circuit coupled to first and second nodes. A capacitance circuit and a slew rate control circuit are coupled between the first and second nodes. The regulator circuit is coupled to charge a capacitance of the capacitance circuit with a charge current. The slew rate control circuit is coupled to control a change in voltage over change in time between the first and second nodes during a power up mode of the circuit. The slew rate control circuit further includes a switch and a resistor. The slew rate control circuit is coupled to switch the switch in response to a voltage between the first and second nodes. A voltage drop across the resistor is limited to a base-emitter voltage drop of a transistor coupled between the first and second nodes to set the change in voltage over change in time. | 03-22-2012 |
20120146715 | Temperature Independent Reference Circuit - A temperature independent reference circuit includes first and second bipolar transistors with commonly coupled bases. First and second resistors are coupled in series between the emitter of the second bipolar transistor and ground. The first and second resistors have first and second resistance values, R | 06-14-2012 |
20120161739 | VARIABLE TIME CLAMP FOR A POWER SUPPLY CONTROLLER - An example integrated circuit for use in a power supply includes a feedback terminal and a controller having a variable time clamp (VTC). The feedback terminal is to be coupled to receive a feedback signal and the controller is to be coupled to enable or disable the conduction of a power switch during a switching cycle in response to the feedback signal. The controller includes a current limit comparator coupled to terminate the conduction of the power switch during an enabled switching cycle in response to a current through the power switch exceeding a variable current limit. The VTC is coupled to clamp the feedback terminal to a voltage for a clamp time that is responsive to the variable current limit. | 06-28-2012 |
20120163043 | METHOD AND APPARATUS TO REGULATE AN OUTPUT VOLTAGE OF A POWER CONVERTER AT LIGHT/NO LOAD CONDITIONS - An example controller for a primary side control power converter includes a feedback circuit, a driver circuit, and an adjustable voltage reference circuit. The feedback circuit is coupled to compare a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit is coupled to output a switching signal to control a switch of the power converter to regulate an output of the power converter in response the feedback circuit. The adjustable voltage reference circuit is coupled to adjust the voltage reference such that the bias winding voltage is adjusted nonlinearly in response to a load condition at the output of the power converter. The adjustable voltage reference circuit is further coupled to detect the load condition in response to the switching signal. | 06-28-2012 |
20120206842 | FAULT CONDITION PROTECTION - A switched mode power supply includes a transformer and an integrated circuit regulator. The integrated circuit regulator is coupled to the transformer and includes switching regulator logic, a counter, and a switching transistor. The regulator logic generates a switching signal in response to the feedback signal. The counter receives the feedback signal, where the feedback signal periodically cycles between a first state and a second state when the switched mode power supply operates normally. An output of the counter indicates an auto-restart mode of the regulator in response to the feedback signal remaining in the first state for a predetermined count due to a fault condition. The switching transistor is coupled to be turned on and off in response to the switching signal when the output of the counter does not indicate the auto-restart mode and is disabled when the output of the counter indicates the auto-restart mode. | 08-16-2012 |
20120218786 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH AN EVENT COUNTER IN A POWER CONVERTER - An example power converter includes an energy transfer element, a switch, and a control circuit. The control circuit includes a drive signal generator and an unregulated dormant mode control circuit. The unregulated dormant mode control circuit renders dormant the drive signal generator thereby ceasing the regulation of the output by the drive signal generator when the energy requirement of the one or more loads falls below a threshold for more than a first period of time. The drive signal generator is unresponsive to changes in the energy requirements of the one or more loads when dormant. The unregulated dormant mode control circuit powers up the drive signal generator after a second period of time has elapsed, such that the drive signal generator is again responsive to changes in the energy requirement of the one or more loads after the second period of time has elapsed. | 08-30-2012 |
20120250368 | POWER SUPPLY CONTROLLER WITH INPUT VOLTAGE COMPENSATION FOR EFFICIENCY AND MAXIMUM POWER OUTPUT - A controller for regulating an output of a power supply includes a logic block and an oscillator. The logic block generates the drive signal to control switching of a power switch in response to a clock signal. The clock signal has a frequency that decreases responsive to a time period of the drive signal, where a decrease in the time period of the drive signal represents an increase in an input voltage of the power supply. The oscillator is coupled to generate the clock signal in response to a waveform having an amplitude swing. The oscillator alters the waveform in response to the time period of the drive signal. | 10-04-2012 |
20120326697 | Temperature Independent Reference Circuit - A temperature independent reference circuit includes first and second bipolar transistors with commonly coupled bases. First and second resistors are coupled in series between the emitter of the second bipolar transistor and ground. The first and second resistors have first and second resistance values, R | 12-27-2012 |
20130021014 | METHOD AND APPARATUS FOR IMPLEMENTING SLEW RATE CONTROL USING BYPASS CAPACITOR - An example circuit includes a capacitance circuit coupled between a first node and a second node. A regulator circuit is coupled to the capacitance circuit to regulate a supply voltage across the capacitance circuit with a charge current during a normal operation mode of the circuit. A slew rate control circuit is coupled to the capacitance circuit and the regulator circuit. The slew rate control circuit is coupled to set a slew rate of a change in voltage over change in time between the first and second nodes during a power up mode of the circuit. The slew rate control circuit includes a transistor coupled between the first and second nodes to shunt excess current from the charge current. | 01-24-2013 |
20130121040 | METHOD AND APPARATUS TO REGULATE AN OUTPUT VOLTAGE OF A POWER CONVERTER AT LIGHT/NO LOAD CONDITIONS - An example controller for a primary side control power converter includes a feedback circuit, a driver circuit, and an adjustable voltage reference circuit. The feedback circuit compares a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit outputs a switching signal having a switching period to control a switch to regulate an output of the power converter in response to the feedback signal and enables or disables a switching period based on the output of the feedback circuit. The adjustable voltage reference circuit adjusts the voltage reference by a first amount in response to a first number of disabled switching periods indicating a first load condition at the output of the power converter and by a second amount in response to a second number of disabled switching periods indicating a second load condition at the output of the power converter. | 05-16-2013 |
20130215650 | VARIABLE TIME CLAMP FOR A POWER SUPPLY CONTROLLER - An example integrated circuit for use in a power supply includes a feedback terminal, a controller and a clamp. The feedback terminal is to be coupled to receive a feedback signal that is representative of a bias voltage across a bias winding of the power supply. The controller is to be coupled to control switching of a power switch included in the power supply in response to the feedback signal. The clamp is coupled to clamp the feedback terminal to a voltage for at least a time that the bias voltage is negative with respect to an input return of the power supply. | 08-22-2013 |
20140153297 | POWER SUPPLY CONTROLLER WITH INPUT VOLTAGE COMPENSATION FOR EFFICIENCY AND MAXIMUM POWER OUTPUT - An apparatus includes an ON/OFF controller for regulating an output of a switched mode power supply by selectively enabling current conduction by a power switch within enabled switching cycles and disabling current conduction by the power switch within disabled switching cycles. The controller includes a logic block and a time-to-frequency converter. The logic block generates a drive signal that enables the current conduction by the power switch within respective enabled switching cycles and disables the current conduction by the power switch within respective disabled switching cycles. The time-to-frequency converter generates a variable-frequency clock signal that defines durations of the switching cycles, where the time-to-frequency converter increases a duration of a switching cycle in response to a decrease in duration of current conduction by the power switch in a previously enabled switching cycle. | 06-05-2014 |
20140204624 | POWER CONVERTER CONTROLLER WITH MULTIPLE POWER SOURCES - A controller includes a bypass terminal, a first power circuit, a second power circuit, and a charging control circuit. The bypass terminal is to be coupled to a bypass capacitor coupled to a secondary side of an isolated power converter. The first power circuit is coupled to the bypass terminal and a first terminal to be coupled to a first node of the secondary side. The first power circuit transfers charge from the first terminal to the bypass terminal for storage on the bypass capacitor. The second power circuit is coupled to the bypass terminal and a second terminal to be coupled to a second node of the secondary side. The second power circuit transfers charge from the second terminal to the bypass terminal for storage on the bypass capacitor. The charging control circuit controls which of the first and second power circuits transfers charge to the bypass terminal. | 07-24-2014 |
20140204626 | RECEIVE CIRCUIT FOR USE IN A POWER CONVERTER - A receive circuit for use in a power converter controller includes a first amplifier coupled to receive an input pulse. A second amplifier is coupled to a first output of the first amplifier. The first output is coupled to be responsive to the input pulse and to a second output of the second amplifier. An output circuit is coupled to generate an output signal in response to the second output. | 07-24-2014 |
20140210446 | METHOD AND APPARATUS FOR IMPLEMENTING SLEW RATE CONTROL USING BYPASS CAPACITOR - An example circuit includes a capacitance circuit, a regulator circuit, and a slew rate control circuit. The capacitance circuit is coupled between a first node and a second node. The regulator circuit is coupled to the capacitance circuit to regulate a supply voltage across the capacitance circuit with a charge current during a normal operation mode of the circuit. The slew rate control circuit is coupled to the capacitance circuit and the regulator circuit. The slew rate control circuit is coupled to lower a slew rate of a change in voltage over change in time between the first and second nodes during a power up mode of the circuit. The slew rate control circuit includes a transistor coupled between the first and second nodes to shunt excess current from the charge current. | 07-31-2014 |
20140254202 | LOW THRESHOLD VOLTAGE COMPARATOR - A voltage comparator includes an amplifier coupled to receive an input signal at an amplifier input and generate an output signal at an amplifier output in response to the input signal. The amplifier includes a current generation circuit coupled to generate a first current flowing through a first branch and a second current flowing through a second branch. A first transistor has a first terminal coupled to the amplifier input and a second terminal coupled to the first branch. A second transistor has a third terminal coupled to the second branch, a fourth terminal coupled to a reference voltage. A second control terminal of the second transistor is coupled to the first control terminal. An output circuit is coupled to the amplifier output to generate a comparator output signal in response to the output signal. The amplifier output is coupled to the second branch. | 09-11-2014 |
20150062974 | Controller IC with Zero-Crossing Detector and Capacitor Discharge Switching Element - An integrated circuit (IC) for controlling the discharge of a capacitor coupled across first and second input terminals of a power converter circuit, wherein the first and second terminals for receiving an ac line voltage. The IC includes a switching element coupled across the first and second input terminals and a detector circuit. The detector circuit including first and second comparators that produce first and second output signals responsive to a zero-crossing event of the ac line voltage. The first and second output signals being used to generate a reset signal coupled to a timer circuit responsive to the zero-crossing event. When the reset signal is not received within a delay time period, the timer circuit outputs a discharge signal that turns the switching element on, thereby discharging the capacitor. | 03-05-2015 |
20150062980 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE WITH AN EVENT COUNTER IN A POWER CONVERTER - A control circuit for use in a power converter includes a drive signal generator coupled to generate a drive signal to control switching of a switch to regulate an output of the power converter. An event detection circuit is coupled to the drive signal generator to indicate if a switching period of one switching cycle of the drive signal exceeds a threshold switching period. An event counter circuit is coupled to the event detection circuit to render dormant the drive signal generator if the event detection circuit indicates a period of a switching cycle of the drive signal exceeds the threshold switching period for a threshold consecutive number of switching cycles. | 03-05-2015 |