Converter for driving a load, a LED driver and a LED lighting apparatus
AssigneeSignify Holding B.V.
InventorsJacob Roelof Tietema, Fleming Hoaming Fu
Life of this patent
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Abstract
A converter for driving a load has a main switch for controlling, at a switching frequency, the path of current flow through a power inductor and power commutation thereof so as to provide an output. A hysteretic control circuit generates a burst signal for turning on and off the power commutation to implement a burst mode operation with a burst frequency lower than the switching frequency. An adjusting circuit adjusts the upper threshold and/or the lower threshold of the hysteretic control in dependence on the detected burst signal. This burst mode hysteresis controlled converter in this way has the hysteresis adapted in dependence on the load being driven so that load regulation problems are reduced.
Claims15
A converter for driving a load, comprising:
- an input line for receiving power;
- a power inductor coupled with the input line;
- a main switch for controlling, at a switching frequency, the path of current flow through the power inductor and power commutation thereof so as to provide an output;
- a hysteretic control circuit for turning off the power commutation when a feedback signal relating to the output reaches an upper threshold of the hysteresis control, and for turning on the power commutation when the feedback signal relating to the output drops to a lower threshold of the hysteresis control, wherein the hysteretic control circuit provides a burst signal for switching on and off of the power commutation to implement a burst mode operation with a burst frequency lower than the switching frequency,
- wherein the converter further comprises an adjusting circuit adapted to:
- detect the burst signal;
- and
- adjust the upper threshold and/or the lower threshold in dependence on the detected burst signal.
Dependencies are inferred from the claim text.