Power Integrations, Inc.

Leif O Lund

Alex B Djenguerian

Balu Balakrishnan

David Kung

Chan Woong Park

Alex B Dienguerian

William Michael Polivka

Sheng Liu

Peter Vaughan

Balu Balakirshnan

Arthur Brian Odell

Sujit Banerjee

Richard A Keller

A power converter includes an energy transfer element coupled between an input and an output of the power converter. A switch is coupled to the energy transfer element and a control circuit. The control circuit includes a drive signal generator to generate a drive signal to control switching of the switch to regulate the 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 for a period of time determined by a timer circuit 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.

Method and apparatus for implementing an unregulated dormant mode with an event counter in a power converter

A controller includes a first power circuit, a second power circuit, and a charging control circuit. The first power circuit is coupled to a bypass terminal and a first terminal to be coupled to receive charge from a secondary winding. The first power circuit transfers charge from the first terminal to the bypass terminal. The second power circuit is coupled to the bypass terminal and a second terminal to be coupled to a receive charge from an output of a power converter. The second power circuit transfers charge from the second terminal to the bypass terminal. The charging control circuit controls which of the first and second power circuits transfers charge to the bypass terminal.

Power converter controller with multiple power sources

A controller for use in a power converter that includes a current limit generator coupled to receive a feedback signal representative of an output of the power converter and generate an initial current limit signal. The controller includes a modulation circuit coupled to output a modulation signal which is a percentage of the initial current limit signal. An arithmetic operator is coupled to receive the initial current limit and selectively receive the modulation signal and output a current limit. A comparator is coupled to receive a current sense signal representative of a switch current conducted by a primary switch. A drive circuit is coupled to generate a drive signal to control switching of the primary switch to regulate the output of the power converter in response to the comparator output signal, and the drive circuit turns off the primary switch when the switch current has reached the current limit.

Load responsive jitter

A method for controlling an output of a power converter with a control circuit includes generating a drive signal to control switching of a switch to regulate the output of the power converter. It is detected if a switching period of one switching cycle of the drive signal exceeds a threshold switching period. The drive signal is disabled when a period of a switching cycle of the drive signal exceeds the threshold switching period for a threshold consecutive number of switching cycles.

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.

Controller IC with zero-crossing detector and capacitor discharge switching element

A controller for use in a power converter includes a comparator to compare a current sense signal with a current limit to generate a comparator output signal representative of whether a switch current has reached the current limit. A drive circuit controls switching of a power switch to regulate an output of the power converter in response to a feedback signal and the comparator output signal. The drive circuit turns off the power switch in response to the comparator output signal. A current limit generator generates an initial current limit in response to the feedback signal. The current limit is responsive to the initial current limit. A light load sense circuit outputs a light load signal in response to sensing a light load condition of the power converter. A modulation circuit outputs a modulation signal and modulates the initial current limit in response to the light load signal.

A method for controlling an output of a power converter includes switching a switching element with drive signals that are generated for switching a switching element during normal operation when an energy requirement of one or more loads at the output are above a low-load threshold. A non-regulated dormant mode of operation is entered when the flow of energy to the output is detected to be less than the low-load threshold value for more than a first period of time. The control circuit is powered down when in the non-regulated dormant mode of operation the control circuit is unresponsive to stop regulating the flow of energy to the output of the power converter. The control circuit remains in the non-regulated dormant mode of operation for a second period of time before powering up again to resume generating the drive signal and regulating the flow of energy.

A Safe Operating Area (SOA) adaptive gate driver for a switch mode power converter is disclosed. In response to a detection of a fault condition, the SOA adaptive gate driver may limit the peak current in a power transistor (e.g., power MOSFET) of the power converter by limiting the voltage applied to the gate of the power MOSFET or by limiting the current injected into the gate of the power MOSFET. The limited gate voltage or current may increase the margin between an SOA border and the turn-off locus of the drain voltage and current (Vand I) to ensure safe operation of the switch mode power converter during the fault condition.

MOSFET driver with pulse timing pattern fault detection and adaptive safe operating area mode of operation

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.

Power supply controller with input voltage compensation for efficiency and maximum power output

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.

A controller for a power converter that may sense whether the power converter is in a light load condition. If the power converter is a light load condition, the switching frequency may be within the audible noise range. Once the controller senses the light load condition, the controller may modulate the switching frequency of the power switch such that the switching frequency is no longer within the audible noise range. The controller comprises of a current limit generator coupled to generate an initial current limit signal and receive a feedback signal. The controller may sense a light load condition of the power converter and output a light load signal. As a result of the light load signal, the controller may modulate the initial current limit in response to the light load signal indicating a light load condition.

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.

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.

Receive circuit for use in a power converter

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.

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San Jose, CA, United States of America

Leif O Lund