Abstract: A control circuit used in a resonant converter with a switching circuit and a resonant circuit is provided, the switching circuit has a high side transistor and a low side transistor, the resonant circuit has a resonant capacitor and a resonant inductor. The control circuit includes: a calculating module used to generate an output current calculating value based on a voltage across the resonant capacitor and a correction signal at an off moment of the high side transistor; a comparing module used to compare the output current calculating value with a burst mode threshold value and generate a burst mode control signal by comparing the output current calculating value with the burst mode threshold value; and a switching control module used to control the resonant converter to work in a burst mode or a normal mode based on the burst mode control signal.

Abstract: A switching mode power supply preventing false triggering of an over current protection due to a surge pulse. The switching mode power supply has a switch and an inductor. An inductor current flows through the inductor. The switching mode power supply turns off the switch and meanwhile starts timing for a preset period of time when the inductor current is larger than a preset value. The switch is kept off during the preset period of time and is then turned on when the preset period of time expires.

Abstract: A control circuit used in a resonant converter with a switching circuit and a resonant circuit is provided, the switching circuit has a high side transistor and a low side transistor, the resonant circuit has a resonant capacitor and a resonant inductor. The control circuit includes: a calculating module used to generate an output current calculating value based on a voltage across the resonant capacitor and a correction signal at an off moment of the high side transistor; a comparing module used to compare the output current calculating value with a burst mode threshold value and generate a burst mode control signal by comparing the output current calculating value with the burst mode threshold value; and a switching control module used to control the resonant converter to work in a burst mode or a normal mode based on the burst mode control signal.

Abstract: A switching mode power supply preventing false triggering of an over current protection due to a surge pulse. The switching mode power supply has a switch and an inductor. An inductor current flows through the inductor. The switching mode power supply turns off the switch and meanwhile starts timing for a preset period of time when the inductor current is larger than a preset value. The switch is kept off during the preset period of time and is then turned on when the preset period of time expires.

Abstract: The present invention provides a synchronous rectification control circuit, a method and a flyback switching circuit. A drive circuit outputs a drive signal to control the turn-on and turn-off of a synchronous rectification transistor; a threshold comparison circuit controls the drive circuit to output a pull-up drive signal to turn on the synchronous rectification transistor when a drain-source voltage is lower than a preset low threshold voltage and controls the drive circuit to output a pull-down drive signal to turn off the synchronous rectification transistor when the drain-source voltage is higher than or equal to a preset high threshold voltage; a voltage regulation control circuit controls the drive circuit to output a drive signal for pulling up a voltage of the drive signal to a preset pull-up voltage high value when the drain-source voltage is lower than a preset voltage regulation reference value.

Abstract: The present invention provides a synchronous rectification control circuit, a method and a flyback switching circuit. A drive circuit outputs a drive signal to control the turn-on and turn-off of a synchronous rectification transistor; a threshold comparison circuit controls the drive circuit to output a pull-up drive signal to turn on the synchronous rectification transistor when a drain-source voltage is lower than a preset low threshold voltage and controls the drive circuit to output a pull-down drive signal to turn off the synchronous rectification transistor when the drain-source voltage is higher than or equal to a preset high threshold voltage; a voltage regulation control circuit controls the drive circuit to output a drive signal for pulling up a voltage of the drive signal to a preset pull-up voltage high value when the drain-source voltage is lower than a preset voltage regulation reference value.

Abstract: A circuit includes a power supply end, a switching tube and a first loop connected to the power supply end in order, a second loop, and a load. The power supply end provides an input voltage for the circuit through a positive busbar and a negative busbar. The first loop includes a first capacitor, a first inductor, and a first freewheeling diode. When the switching tube is on, the first inductor is charged by the input voltage through the first capacitor; and when the switching tube is off, the first inductor discharges through the first capacitor and the first freewheeling diode. The second loop includes a second inductor coupled with the first inductor, a second capacitor and a second freewheeling diode forming a loop with the second inductor. The second capacitor and the first capacitor are connected in series.

Abstract: A switching mode power supply with resonant technology. The switching mode power supply current uses current polarity evaluation to avoid capacitive mode by triggering the capacitive protection if the evaluation indicates that the system will enter capacitive mode.

Abstract: A resonant converter has a switching circuit having a first switch and a second switch, a control circuit and a resonant circuit. The control circuit has a slope sensing circuit providing a slope sense signal based on a voltage variation at the common node of the first switch and the second switch, a slope judge circuit providing a slope judge signal, and a turn-ON control circuit providing a first reset signal to adjust a first dead-time period from turning OFF the first switch to turning ON the second switch based on the slope judge signal, the slope signal, and a current flowing through the resonant tank, and providing a second reset signal to adjust a second dead-time period from turning OFF the second switch to turning ON the first switch based on the slope judge signal, the slope signal, and the current flowing through the resonant tank.

Abstract: A PFC circuit includes: a switching circuit having a power switch; an on time control circuit for controlling an on time period of the power switch; a first off time control circuit; a second off time control circuit; and a logic circuit selectively controls the power switch working under CCM or DCM; when working under CCM, the first off time control circuit controls an off time period of the power switch and when working under DCM, the second off time control circuit controls the off time period of the power switch.

Abstract: A resonant converter has a switching circuit having a first switch and a second switch, a control circuit and a resonant circuit. The control circuit has a slope sensing circuit providing a slope sense signal based on a voltage variation at the common node of the first switch and the second switch, a slope judge circuit providing a slope judge signal, and a turn-ON control circuit providing a first reset signal to adjust a first dead-time period from turning OFF the first switch to turning ON the second switch based on the slope judge signal, the slope signal, and a current flowing through the resonant tank, and providing a second reset signal to adjust a second dead-time period from turning OFF the second switch to turning ON the first switch based on the slope judge signal, the slope signal, and the current flowing through the resonant tank.

Abstract: A switching mode power supply with resonant technology. The switching mode power supply current uses current polarity evaluation to avoid capacitive mode by triggering the capacitive protection if the evaluation indicates that the system will enter capacitive mode.

Abstract: The present disclosure discloses a power converter providing a low output voltage from an offline AC. The power converter defines a voltage window for the input AC signal. Inside the voltage window, the rectified DC waveform is passed through to the output and the storage capacitor; outside the voltage window, the power converter is idle (or the output is blocked from input) and let the output storage capacitor alone supply the load.

Abstract: An off-line regulator has a rectification circuit configured to rectify an AC line voltage into a rectified line voltage, a pass device coupled between the rectified line voltage and a first capacitor, and a converter. The pass device is configured to be turned ON or OFF according to a comparison signal indicating whether the rectified line voltage is over a threshold voltage. The first capacitor delivers an interim voltage into the converter which supplies power to a load. Wherein a second capacitor coupled across a driver which driving the pass device is charged by the first capacitor when the comparison signal is at a first state, and the driver is boosted when the comparison signal is at a second state.

Abstract: A PFC circuit includes: a switching circuit having a power switch; an on time control circuit for controlling an on time period of the power switch; a first off time control circuit; a second off time control circuit; and a logic circuit selectively controls the power switch working under CCM or DCM; when working under CCM, the first off time control circuit controls an off time period of the power switch and when working under DCM, the second off time control circuit controls the off time period of the power switch.

Abstract: The present invention discloses an off-line regulator. The off-line regulator comprises a rectification circuit configured to rectify an AC line voltage into a rectified line voltage; a pass device coupled between the rectified line voltage and a first capacitor, the pass device is configured to be turned ON or OFF according to a comparison signal indicating whether the rectified line voltage is over a threshold voltage. The first capacitor delivers an interim voltage into a converter which supplies power to a load. Wherein a second capacitor coupled across a driver which driving the pass device is charged by the first capacitor when the comparison signal is at a first state, and the driver is boosted when the comparison signal is at a second state.

Abstract: The present disclosure discloses a power converter providing a low output voltage from an offline AC. The power converter defines a voltage window for the input AC signal. Inside the voltage window, the rectified DC waveform is passed through to the output and the storage capacitor; outside the voltage window, the power converter is idle (or the output is blocked from input) and let the output storage capacitor alone supply the load.

Abstract: A method for simulating an image captured at a long exposure time (“simulated image”), includes (1) capturing each of first, second, and third images at a short exposure time, (2) determining a first relative motion between the first and the second images, (3) transforming the first image to remove the first relative motion, (4) determining a second relative motion between the third and the second images, (5) transforming the third image to remove the second relative motion, and (6) combining the first, the second, and the third images to form the simulated image. Relative motions between images are determined by matching blocks at multiple resolutions to determine corresponding points between the images. Transformation to remove relative motion is determined by fitting corresponding points between the images using a minimum square error (MSE) algorithm in a random sample consensus (RANSAC) framework.

Abstract: A method for enhancing a video includes applying a linear histogram stretch, a gamma correction, and sigma row, column, and temporal filters to the video.

Abstract: A method for enhancing a video includes applying a linear histogram stretch, a gamma correction, and sigma row, column, and temporal filters to the video.