Abstract: A power switch includes a bridge-connected switching circuit with (1) a pair of MOSFETs back-to-back in series between line and load connections, an interconnection point of the MOSFETs being a first common connection, and (2) a pair of diodes back-to-back between the line and load connections, an interconnection point of the diodes being a second common connection. A line/load controller has supply inputs connected to the first and second common connections for receiving operating power, and (1) places both MOSFETs in the ON state to deliver normal operating current to the load for normal operation, and (2) places both MOSFETs in the OFF state to deliver (by body diode conduction) a substantially reduced leakage current to the load when the load is not powered for normal operation, the leakage current providing the operating power to the line/load controller.

Abstract: A power switch includes a bridge-connected switching circuit with (1) a pair of MOSFETs back-to-back in series between line and load connections, an interconnection point of the MOSFETs being a first common connection, and (2) a pair of diodes back-to-back between the line and load connections, an interconnection point of the diodes being a second common connection. A line/load controller has supply inputs connected to the first and second common connections for receiving operating power, and (1) places both MOSFETs in the ON state to deliver normal operating current to the load for normal operation, and (2) places both MOSFETs in the OFF state to deliver (by body diode conduction) a substantially reduced leakage current to the load when the load is not powered for normal operation, the leakage current providing the operating power to the line/load controller.

Abstract: A regulated switching power converter generates a converter output having first and second regulated output values under corresponding operating conditions. The converter output transitions between the first and second output values in response to transition of a trigger signal in a transition window between first and second trigger values. A transition step function is based on transition amplitude, transition interval and number of steps, the transition amplitude being a difference between the first and second regulated output values, and the transition interval being a difference between the first and second trigger values. The transition step function generates a step-like transition signal based on values of the trigger signal between the first and second trigger values. During operation in the transition window, the step-like transition signal is included in the regulation reference value to generate a step-like transition of the converter output between the first and second regulated output values.

Abstract: A regulated switching power converter generates a converter output having first and second regulated output values under corresponding operating conditions. The converter output transitions between the first and second output values in response to transition of a trigger signal in a transition window between first and second trigger values. A transition step function is based on transition amplitude, transition interval and number of steps, the transition amplitude being a difference between the first and second regulated output values, and the transition interval being a difference between the first and second trigger values. The transition step function generates a step-like transition signal based on values of the trigger signal between the first and second trigger values. During operation in the transition window, the step-like transition signal is included in the regulation reference value to generate a step-like transition of the converter output between the first and second regulated output values.

Abstract: A power supply for an LED lamp has a set of coupled coils, primary-side power circuitry including a converter power switch for conducting input power, and secondary-side power circuitry including a dimming power switch. Power control circuitry includes converter control circuitry which generates a converter control signal for the converter power switch to maintain a desired undimmed level of lamp current at a normal operating value of a lamp voltage. Dimming control circuitry generates a dimming control signal for the dimming power switch to pulse-width modulate the lamp current at a duty cycle corresponding to a desired dimming. Operation of the converter control circuitry is modified during dimming to prevent an automatic increase of the lamp voltage in response to a decrease in lamp current, avoiding undesirable overshooting of the lamp current and providing more accurate and effective control over dimming operation.

Abstract: A power supply for an LED lamp has a set of coupled coils, primary-side power circuitry including a converter power switch for conducting input power, and secondary-side power circuitry including a dimming power switch. Power control circuitry includes converter control circuitry which generates a converter control signal for the converter power switch to maintain a desired undimmed level of lamp current at a normal operating value of a lamp voltage. Dimming control circuitry generates a dimming control signal for the dimming power switch to pulse-width modulate the lamp current at a duty cycle corresponding to a desired dimming. Operation of the converter control circuitry is modified during dimming to prevent an automatic increase of the lamp voltage in response to a decrease in lamp current, avoiding undesirable overshooting of the lamp current and providing more accurate and effective control over dimming operation.