Abstract: A switching power converter is provided that extrapolates from a reference voltage during dead periods of a rectified input voltage as determined from a comparison of an Isense voltage to a current threshold.

Abstract: A switching power converter is provided that cycles a power switch during a group pulse mode of operation to produce a train of pulses within a group period responsive to a control voltage being within a group mode control voltage range. Depending upon the control voltage, the number of pulses in each train of pulses is varied to provide a linear power delivery to the load.

Abstract: A power supply can be operated in a low power mode by adjusting the pulses provided to a power supply switch until a pulse resulting in a reduced amount of power that exceeds a minimum power threshold required by a load coupled to the power supply switch is identified. For each successive switching cycle, a pulse causing a lower power to be provided to the load is produced. When a pulse is produced that causes a power to be provided to the load that does not exceed the minimum power threshold required by the load, a subsequent pulse is produced that causes a greater power to be provided to the load than the previous pulse. If the greater power exceeds the minimum power threshold, the subsequent pulse is stored and similar pulses are provided for the remainder of the low power mode.

Abstract: A variable-level flyback power converter is configured to provide an accurate output voltage at various regulation levels. The variable-level flyback power converter may include a switch coupled to a secondary winding of a transformer, a diode coupled to a primary winding of the transformer, and a controller coupled to the switch. The controller may scale an initial reference voltage based on a desired output voltage and a forward voltage drop across the diode, compare the scaled reference voltage with a feedback voltage sensed at an auxiliary winding of the transformer to generate an error signal, and modulate a pulse signal provided to the switch based on the error voltage.

Abstract: The embodiments disclosed herein describe a set of fault detection circuits for LED circuits in an LED channel. A first fault detection circuit is configured to detect a short fault across one or more LEDs. A second fault detection circuit is configured to detect an open fault across an LED. A third fault detection circuit is configured to detect a short across an LED channel transistor. A fourth fault detection circuit is configured to detect an LED channel sense resistor open fault. A fifth fault detection circuit is configured to detect if the LED channel is being intentionally unused. These fault detect circuits can be implemented in a fault detection integrated circuit coupled to the LED channel.

Abstract: A switching power converter controller is provided that transitions between constant voltage pulse frequency modulation operation and constant current operation responsive to a comparison of a peak voltage for the constant voltage pulse frequency modulation operation and a peak voltage for the constant current operation.

Abstract: A flyback converter is provided with a controller that is configured to analyze the reflected feedback voltage waveforms to determine the presence of a ground connection fault for the auxiliary winding.

Abstract: A power supply can be operated in a low power mode by adjusting the pulses provided to a power supply switch until a pulse resulting in a reduced amount of power that exceeds a minimum power threshold required by a load coupled to the power supply switch is identified. For each successive switching cycle, a pulse causing a lower power to be provided to the load is produced. When a pulse is produced that causes a power to be provided to the load that does not exceed the minimum power threshold required by the load, a subsequent pulse is produced that causes a greater power to be provided to the load than the previous pulse. If the greater power exceeds the minimum power threshold, the subsequent pulse is stored and similar pulses are provided for the remainder of the low power mode.

Abstract: A method of monitoring a process of powering an electronic device through a cable assembly is proposed. The cable assembly comprises a cable which is connected between a power supply and the electronic device. The method comprises generating a synchronization signal, generating a test signal based on the synchronization signal and applying the test signal to one end of the cable, detecting a response signal at the one end of the cable, the response signal resulting from applying the test signal to the cable assembly, and determining, based on the response signal and the synchronization signal, a first and a second quantity indicative of a real part and an imaginary part of the impedance of the cable assembly, respectively. Further, an apparatus for monitoring a process of powering an electronic device through a cable assembly is proposed.

Abstract: A flyback converter is provided with a synchronous rectifier (SR) controller including a pulse linear regulator (PLR) charging path and an LDO charging path. The SR controller is configured to monitor the switching period and/or duty cycle of a power switch in the flyback converter to select between the PLR and LDO charging paths.

Abstract: A multi-mode control scheme for an LED lamp system uses the detected firing angle of an AC input voltage waveform to select from multiple regulation modes. In operation, a current controller compares the detected firing angle to one or more specified thresholds and selects the appropriate regulation scheme based on the comparison result. When the detected firing angle is less than a first firing angle threshold, the controller employs a current shaping regulation mode. When the detected firing angle is greater than a second firing angle threshold, the controller employs a switching cycle-I Peak modulation regulation mode. And when the detected firing angle is greater than the first firing angle threshold and less than the second firing angle threshold, the controller employs a hybrid regulation mode.

Abstract: A switching power converter is configured to control switching noise by implementing a plurality of pulse width modulation modes of operation. The peak current in each pulse width modulation mode of operation is controlled so that an output power for the switching power converter is continuous with regard to transitions between the pulse width modulation modes.

Abstract: One embodiment of a disclosed cable protection device connected between the positive and negative wires of the cable that provides an efficient method of protection from overheating of the device due to changes in temperatures with minimal power dissipation. The cable protection device includes a temperature monitoring device that continuously senses the temperature of the cable and device to check for overheating. A controller connected to the temperature monitor sends out an alarm message and a control signal to either an actuator circuit or a crowbar function circuit. The actuator circuit can send out current pulses to the adapter indicating the adapter to lower its current limit, so that the device can still keep charging and is not over heated. The crowbar function circuit causes the adapter to turn off power to the cable in order to provide burning of the device or connector due to overheating.

Abstract: An arbitrary alignment is provided for a series of pulses controlling a switch that in turn controls a current in an LED. Each pulse is generated according to a target time responsive to a reference time in a corresponding cycle of a synchronization clock. Each pulse has a leading portion that precedes its target time and a trailing portion subsequent to its target time. The arbitrary alignment defines the relative size of the leading portion to the trailing portion such that these relative sizes are incrementally changed across successive ones of the pulses.

Abstract: A switching power converter may include a power switch coupled to a primary winding of a transformer, and a primary controller configured to turn on and off the power switch, a synchronous rectifier switch coupled to a secondary winding of a transformer, and a synchronous rectifier controller configured to turn on and off the synchronous rectifier switch. The synchronous rectifier controller may monitor a voltage across the synchronous rectifier switch. The synchronous rectifier controller may detect a fault condition responsive to the voltage reaching a turn-off voltage threshold before a minimum on-time timer expires. The synchronous rectifier controller may detect a fault condition responsive to the synchronous rectifier switch being turned off at the same time, immediately after, or within a timing guardband after the minimum on-time timer expires. The synchronous rectifier controller may adaptively increase a minimum off-time period for the synchronous rectifier switch.

Abstract: An LED lamp comprises one or more LEDs and an LED driver receiving an input signal from a dimmer switch indicative of an amount of dimming for the LED lamp. The LED driver controls regulated current through the one or more LEDs based on the input signal such that an output light intensity of the one or more LEDs substantially corresponds to the amount of dimming for the LED lamp. A regulated output provides operating power for the LED driver. A controller regulates the regulated output to power the LED driver. The controller selects a power source for charging the regulated output from two or more power sources, and the regulated output is charged using the power source selected by the controller.

Abstract: A power converter with a dynamic preload. The power converter includes a magnetic component coupled between an input and an output of the power converter. The output of the power converter has an output voltage for providing power to a load. A switch is adapted to control current through the magnetic component according to on and off times of the switch. A dynamic preload circuit is coupled to the output of the power converter. The dynamic preload has loading characteristics that are adjusted responsive to a signal indicative of an output voltage at the output of the power converter.

Abstract: A LED lighting system, such as a dimmable LED lamp, that may simulate the performance of an incandescent bulb. LED strings of different colors may be connected to the output of a single LED driver that regulates an overall intensity of light produced by the LED lighting system. The color of the LED lighting system may be controlled by circuitry, such as one or more switches, that allocates current between the LED strings to change the color temperature of light emitted by the LED lighting system as the light intensity changes.

Abstract: A switching power converter is provided that extrapolates from a reference voltage during dead periods of a rectified input voltage as determined from a comparison of an Isense voltage to a current threshold.

Abstract: An apparatus comprises an output port to be connected to a load; a first input port to receive a first input signal; and a second input port coupled between the first input port and the output port, to receive a second input signal. The apparatus further comprises a coupling circuit to couple the second input signal to the output port and a frequency isolation circuit that has a frequency response to propagate the first input signal to the output port but prevent the second input signal from propagating to the first input port. The apparatus also comprises a detection circuit to determine a voltage of an output signal at the output port, the output signal having a first amplitude range with a load absent at the output port and having a second amplitude range lower than the first amplitude range with the load present at the output port.