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 data transmission method is provided for transmitting analog data through an isolating device using a calibration input pulse and a data input pulse. The analog data may represent, for example, the desired dimming value for a flyback converter powering a solid state lighting system.

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 data transmission method is provided for transmitting analog data through an isolating device using a calibration input pulse and a data input pulse. The analog data may represent, for example, the desired dimming value for a flyback converter powering a solid state lighting system.

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 is provided that switches between low-bandwidth PI control and a high-speed control of an output voltage responsive to comparing the output voltage to an upper output voltage limit and to a lower output voltage limit. The switching power converter adapts the upper and lower voltage limits responsive to a load demand.

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: This specification relates to a method and a system for detecting light emitting diode (LED) short circuit in a plurality of LED strings or detecting matching among the plurality of LED strings, wherein one end of each of the plurality of LED strings is connected to a same output end of a power supply, and the other end is respectively connected to a corresponding switch. According to the present invention, first current of each of LED strings is obtained when the output end of the power supply outputs a first voltage; differences between the minimum of the first currents of LED strings and other first currents are calculated; the differences are compared with a comparing threshold; it is determined that the LED strings corresponding to the other currents for which differences are larger than the comparing threshold include short circuit or mismatch with the LED string corresponding to the minimum current. Accordingly, it is possible to reduce the number of pins and area of a control chip.

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: This specification relates to a method and a system for detecting light emitting diode (LED) short circuit in a plurality of LED strings or detecting matching among the plurality of LED strings, wherein one end of each of the plurality of LED strings is connected to a same output end of a power supply, and the other end is respectively connected to a corresponding switch. According to the present invention, first current of each of LED strings is obtained when the output end of the power supply outputs a first voltage; differences between the minimum of the first currents of LED strings and other first currents are calculated; the differences are compared with a comparing threshold; it is determined that the LED strings corresponding to the other currents for which differences are larger than the comparing threshold include short circuit or mismatch with the LED string corresponding to the minimum current. Accordingly, it is possible to reduce the number of pins and area of a control chip.

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 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 lighting system and a method are provided with an adaptive power balancing scheme which reduces or eliminates flicker by sensing the operation of a lamp that is connected to an electronic transformer and adaptively controlling the drive circuit of the lamp to prevent unexpected reset of the electronic transformer. There is provided a lamp with a light source and a drive circuit for the light source; said drive circuit has a power stage for regulating a voltage supplied to the light source, an energy storage device, and control means arranged to selectively disable the power stage. Power is provided to the light source by the energy storage device when the power stage is disabled.

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 is provided that switches between low-bandwidth PI control and a high-speed control of an output voltage responsive to comparing the output voltage to an upper output voltage limit and to a lower output voltage limit. The switching power converter adapts the upper and lower voltage limits responsive to a load demand.

Abstract: The present invention provides an apparatus and method for reducing jitter in a periodic signal. The apparatus comprises: a frequency discriminator configured to receive the periodic signal and feedback of an output signal of the apparatus and calculate an estimate value for a length of a current period of the periodic signal; a phase discriminator configured to receive the periodic signal and determine an adjustment factor for the length of the current period of an input signal according to the input signal in a previous period of the periodic signal and the output signal in the previous period of the apparatus; and an adjustor configured to determine the period length of the output signal in the current period according to the estimate value for the length of the current period and the adjustment factor for the length of the current period.

Abstract: This specification relates to a method and a system for detecting light emitting diode (LED) short circuit in a plurality of LED strings or detecting matching among the plurality of LED strings, wherein one end of each of the plurality of LED strings is connected to a same output end of a power supply, and the other end is respectively connected to a corresponding switch. According to the present invention, first current of each of LED strings is obtained when the output end of the power supply outputs a first voltage; differences between the minimum of the first currents of LED strings and other first currents are calculated; the differences are compared with a comparing threshold; it is determined that the LED strings corresponding to the other currents for which differences are larger than the comparing threshold include short circuit or mismatch with the LED string corresponding to the minimum current. Accordingly, it is possible to reduce the number of pins and area of a control chip.

Abstract: The present invention provides an apparatus and method for reducing jitter in a periodic signal. The apparatus comprises: a frequency discriminator configured to receive the periodic signal and feedback of an output signal of the apparatus and calculate an estimate value for a length of a current period of the periodic signal; a phase discriminator configured to receive the periodic signal and determine an adjustment factor for the length of the current period of an input signal according to the input signal in a previous period of the periodic signal and the output signal in the previous period of the apparatus; and an adjustor configured to determine the period length of the output signal in the current period according to the estimate value for the length of the current period and the adjustment factor for the length of the current period.