Abstract: A light emitting diode (LED) driver circuit is configured to drive plural LEDs which are respectively coupled to m scan-lines and n data-lines, wherein m and n are both integers greater than or equal to one. During a driving stage, each of the LEDs is controlled to emit light according to the electrical characteristics on the corresponding scan-line and on the corresponding data-line where the LED is coupled to. The LED driver circuit includes: a power saving control circuit which includes a storage capacitor; a pre-discharging circuit configured to pre-discharge the charges on the m scan-lines to the storage capacitor during a pre-discharging stage; and a pre-charging circuit configured to pre-charge the n data-lines by the charges stored in the storage capacitor during a pre-charging stage.

Abstract: A controller applied to a secondary side of a power convertor includes a sampling/tracking circuit and a comparator. The sampling/tracking circuit is coupled to the secondary side of the power convertor for generating a sampling value corresponding to an output voltage of the power convertor when a sampling signal is enabled, and generating a tracking value corresponding to the output voltage. The comparator is coupled to the sampling/tracking circuit for generating a warning signal to a primary-side regulation controller of the power converter according to the sampling value and the tracking value during an enabling period of a tracking signal. The primary-side regulation controller adjusts a frequency of a gate control signal according to the warning signal, and the sampling signal and the tracking signal are not enabled simultaneously.

Abstract: A controller applied to a secondary side of a power convertor includes a sampling/tracking circuit and a comparator. The sampling/tracking circuit is coupled to the secondary side of the power convertor for generating a sampling value corresponding to an output voltage of the power convertor when a sampling signal is enabled, and generating a tracking value corresponding to the output voltage. The comparator is coupled to the sampling/tracking circuit for generating a warning signal to a primary-side regulation controller of the power converter according to the sampling value and the tracking value during an enabling period of a tracking signal. The primary-side regulation controller adjusts a frequency of a gate control signal according to the warning signal, and the sampling signal and the tracking signal are not enabled simultaneously.