Linear Technology Corporation

Linear Technology Holding LLC

Dongwon Kwon

Joshua William Caldwell

Lucas Andrew Milner

A synchronous converter that includes a power source, an inductor, an output terminal, and a control circuit. The control circuit may include: an electronic energizing switch that, when activated, delivers energy from the power source to the inductor; an electronic de-energizing switch that, when activated, delivers energy from the inductor to the output terminal, the electronic de-energizing switch including a body diode; and an electronic pull-down switch that, when activated, turns off the electronic de-energizing switch, redirects current flowing though the body diode of the electronic de-energizing switch, and removes charge from the body diode of the electronic de-energizing switch. The electronic energizing switch and the electronic de-energizing switch may never both be activated at the same time.

Minimizing body diode conduction in synchronous converters

Techniques are provided for low, or deep, dimming of a light-emitting diode (LED) load. In an example, a method of adjusting an initial voltage of a driver circuit for an LED load can include providing current to an LED load from a power stage of the driver during an on-time of a pulse-width modulation (PWM) cycle, receiving error current information of the driver circuit at a low-dimming control circuit of the driver, and adjusting a voltage of an output capacitor coupled to the driver during an off-time of the PWM cycle, the charge adjustment based on the error current information.

LED dimming

A method and system of driving an LED load. There is a power stage that is configured to deliver a level of current indicated by a control signal to the LED load when a PWM signal is ON and stop delivering the level of current when the PWM signal is OFF. There is a feedback circuit that is configured to generate the operating point signal, which causes the power stage to deliver a level of current indicated by the control signal, when the PWM signal is ON. A store and hold circuit is configured to store an information indicative of a level of the operating point signal just after the PWM signal is turned OFF and cause the operating point signal to be at that level just before the PWM signal is turned ON.

Maintaining LED driver operating point during PWM off times

A method and system of driving an LED load. A driver is configured to deliver a level of current indicated by a control signal to the LED load when a PWM signal is ON and stop delivering the level of current when the PWM signal is OFF. An output capacitance element is coupled across a differential output of the LED driver. A feedback path, having a store circuit, is configured to store an information indicative of a first voltage level across the output capacitance element as a stored feedback reference signal just after the PWM signal is turned OFF. The feedback path causes the voltage across the output capacitance element to be at the first voltage level just before the PWM signal is turned ON.

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San Jose, CA, United States of America

Dongwon Kwon