Atmel Corporation

Nanowatt Inc.

Wenbo Liang

Sean S Chen

Dilip Sangam

Hong Zhang

Ying Li

San Hwa Chee

Edward Er Deng

An AC-DC converter includes an AC voltage source, a rectifier, and a rectifier control circuit. The rectifier includes a field effect transistor (FET) having a source, a drain, and a gate. The drain of the FET is coupled to the AC voltage source, and the source is coupled to ground. The rectifier control circuit is coupled to the gate of the FET. The rectifier control circuit is configured to provide a ramp voltage to regulate the FET after the AC voltage source is turned off.

AC-DC converter with adaptive regulation circuit

A circuit for driving light emitting elements, such as LEDs, includes a first transistor having a source coupled to ground through a first resistive element, and a second transistor having a gate electrically coupled to a gate of the first transistor, a source electrically coupled to ground, and a drain for electrical connection to a first group of light emitting elements. The circuit also includes circuitry to provide a predetermined voltage at the source of the first transistor, circuitry to compensate for a difference in respective gate-source voltages of the first and second transistors, and circuitry to compensate for a difference in respective drain-source voltages of the first and second transistors. In some implementations, the circuit can achieve relatively low power consumption.

Driving circuits for light emitting elements

A fault protection and correction circuit for the control of a power converter is disclosed. An example circuit generates a waveform that drives a switch on or off and controls the power converter. The controller circuit in addition to power factor correction (PFC) circuitry includes a first and a second shut down mode modules, both of them cause the switching to stop. The circuit includes a module for receiving fault events. When a fault occurs, the controller enters the second shut down mode. The controller stays in the second shut down mode if the required current for this mode can be provided by the outside circuitry. Otherwise, the controller enters the first shut down mode that requires less current and subsequently restarts the controller. By modifying the outside circuitry the controller can respond differently to fault events.

Fault protection and correction of line and load faults

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Wenbo Liang