Microsemi Corporation

Etienne Colmet-Daage

Pierre R Irissou

Bernard Drexler

Sam Seiichiro Ochi

Stephane Legoff

An over-current protection apparatus constituted of: a transistor disposed on a substrate; a first thermal sense device arranged to sense a temperature reflective of a junction temperature of the transistor; a second thermal sense device arranged to sense a temperature reflective of a temperature of a casing surrounding the substrate; and a control circuitry, arranged to alternately: responsive to the sensed temperature by the first thermal sense device and the sensed temperature of the second thermal sense device being indicative that the temperature difference between the transistor junction and the substrate casing is greater than a predetermined value, switch off the transistor; and responsive to the sensed temperature by the first thermal sense device and the sensed temperature by the second thermal sense device being indicative that the temperature difference between the transistor junction and the substrate casing is not greater than the predetermined value, switch on the transistor.

Over-current protection apparatus and method

Methods, systems, and devices are described for providing fault monitoring for light emitting diode (LED) circuits. Embodiments receive an indication from a fault control module that a fault has occurred in a portion of an LED module (e.g., a series string of LEDs). The fault may represent an open fault or a closed fault condition. In some embodiments, a monitoring module receives the fault indication and generates a further representation that the fault has occurred (e.g., for use by external components or systems). In other embodiments, the monitoring module in configured to further indicate which in the LED module has failed, and/or in what fault condition (e.g., open or closed).

Light emitting diode fault monitoring

Methods, systems, and devices are described for sensing a phase-cut dimming signal and outputting a control signal compatible with a switching power circuit. Embodiments of the invention generate at least one of a low-frequency pulse-wave-modulated control signal, an analog output control signal, or a digital (e.g., higher-frequency pulse-wave-modulated) output control signal. Some embodiments further provide preloading and/or startup control functionality to allow proper functioning of the circuitry under small-conduction-angle (i.e., highly dimmed) conditions.

Methods and apparatuses for phase-cut dimming at low conduction angles

Methods, systems, and devices are provided for optimizing a bus voltage supplied to a switching power converter to keep the duty cycle of the switching power converter to within a desirable operating range. In some embodiments, the duty cycle of the switching signal used to drive the switching power converter is monitored (e.g., indirectly) to determine whether the duty cycle is approaching an undesirable level. For example, as the duty cycle decreases (e.g., approaches or crosses a certain threshold), embodiments decrease the bus voltage. This may, in turn, allow the switching power converter to output substantially the same output to the load, while using a more efficient (e.g., larger) duty cycle. Certain embodiments use similar techniques, along with certain bus voltage optimization techniques, to control a bus voltage as a function of feedback from multiple switching power converters.

Bus voltage optimizer for switched power converter

Methods, systems, and devices are described for providing output (e.g., current) sensing and feedback in high-voltage switching power converter topologies. Certain aspects of high voltage switching converter topologies may make output (e.g., current) sensing difficult. In some embodiments, a sampling module implements sample-and-hold techniques in a low-side switch converter topology to provide reliable current sensing. Embodiments of the sampling module provide certain functionality, including integration, blanking, buffering, and adjustable sampling frequency. Further, some embodiments include feedback functionality for generating a converter driver signal (for driving the switching converter) and/or a sample driver signal (for driving the sampling module) as a function of sensed output feedback from the sampling module.

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Los Altos, CA, United States of America

Etienne Colmet-Daage