Patent application number | Description | Published |
20090262840 | Synchronization Signal Extraction Device and Related Method - A synchronization signal extraction device includes a signal reception terminal for receiving a composite video signal, a threshold voltage adjuster coupled to the signal reception terminal for adjusting a threshold voltage to a ratio of a first characteristic level and a second characteristic level of the composite video signal according to the first characteristic level and the second characteristic level, a slicer coupled to the signal reception terminal and the threshold voltage adjuster for slicing the composite video signal to extract a synchronization signal in the composite video signal, and a signal output terminal coupled to the slicer for outputting the extracted synchronization signal. | 10-22-2009 |
20100002143 | DISPLAY APPARATUS AND PHASE DETECTION METHOD THEREOF - A display apparatus including an analog-to-digital converter (ADC) module, a phase detecting module, and a clock generator is provided. The ADC module is used to receive a first analog video signal, and convert the first analog video signal into a digital signal according to a clock signal. The first analog video signal includes a first synchronous information and a first video information. The phase detecting module is used to receive the digital signal, and output a phase adjustment signal according to a part of the digital signal corresponding to the first synchronous information. The clock generator is used to output the clock signal according to the phase adjustment signal. | 01-07-2010 |
20100215130 | Method and Related Device for Detecting Signals in a TMDS Transmission System - A method for detecting signals in a TMDS transmission system is disclosed. A channel of the TMDS system is established between a receiver and a transmitter. The method includes separating loadings of the receiver from the channel, providing a first reference current in a first differential line of the channel, providing a second reference current in a second differential line of the channel, computing a difference between the first reference current and a current provided by the transmitter via the first differential line to obtain a first current difference, computing a difference between the second reference current and a current provided by the transmitter via the second differential line to obtain a second current difference, and determining an operating state of the transmitter according to the first current difference and the second current difference. | 08-26-2010 |
20140198089 | IMAGE PROCESSING UNIT, IMAGE PROCESSING APPARATUS AND IMAGE DISPLAY SYSTEM - An image processing unit including an always on circuit block and a non-always on circuit block is provided. When operating under a first operation mode, the non-always on circuit block receives a bias voltage from a power supply unit, so as to perform an image processing operation on an image input signal. When operating under a second operation mode, the non-always on circuit block stops receiving the bias voltage from the power supply unit, so as to stop the image processing operation, and at least a microcontroller of the non-always on circuit block is powered down. One of the always on circuit block and the non-always on circuit block controls the power supply unit to stop supplying the bias voltage to the non-always on circuit block according an event trigger signal, such that the non-always on circuit block enters the second operation mode from the first operation mode. | 07-17-2014 |
Patent application number | Description | Published |
20090080676 | Driver circuit and driving method for electrostatic loudspeaker - The present invention discloses a driver circuit for an electrostatic loudspeaker, comprising: a digital modulation encoder for receiving a digital audio signal and a fixed frequency pulse signal, and mixing them by modulation; a digital to analog converter for converting the output of the digital modulation encoder to an analog signal; a transformer for adjusting the voltage amplitude of the analog signal; and a demodulator for demodulating the adjusted analog signal to driver a speaker. | 03-26-2009 |
20100026209 | LED driving circuit and method - A LED driving circuit includes a regulator to provide an output voltage to a LED light source, a current source to control the driving current of the LED light source, and a controller to detect the voltage of the current source to generate a control signal for the regulator to regulate the output voltage at a low level. There are no resistors on the current path established by the LED light source and current source, and the regulator may maintain the voltage of the current source as low as possible, thereby improving the power efficiency and reducing the power consumption. | 02-04-2010 |
20110012551 | SINGLE STAGE LOW BOOST/BUCK RATIO STAND-ALONE SOLAR ENERGY POWER GENERATING CIRCUIT AND SYSTEM THEREOF - A single stage low boost/buck ratio stand-alone solar energy power generating circuit with a system thereof is a simplification of a two-stage type circuit. The two-stage circuit, which has a storage unit, a charging converter circuit for charging the storage unit, and a discharging converter circuit for discharging the stored power to a load, is analyzed and categorized such that a circuit structure is selected via a suitable simplified combination to commonly use the elements constituting the charging and the discharging converter circuits so as to form the single stage circuit with less elements, volume and weight for reducing the production cost of the circuit. | 01-20-2011 |
20110031951 | FREQUENCY MODULATION CONTROL OF A BUCK-BOOST POWER CONVERTER - A control circuit and method are proposed to generate a control signal to operate a buck-boost power stage of a buck-boost power converter to convert an input voltage to an output voltage. The control circuit and method detect the output voltage to generate an error signal, control the frequency of two ramp signals according to the error signal, generate two pulse width modulation signals according to the error signal and the two ramp signals, and generate the control signal according to the two pulse width modulation signals. When the loading of the buck-boost power converter transits from heavy to light, the frequency of the two ramp signals is decreased to improve the efficiency of the buck-boost power converter. The peaks and valleys of the two ramp signals may be adjusted by signals related to the input voltage and the output voltage. | 02-10-2011 |
20110043187 | METHOD AND CIRCUIT FOR TRACKING MAXIMUM POWER OF A PHOTO-VOLTAIC ARRAY - A method and a circuit for tracking maximum power of a photo-voltaic array performs the operation of load increase/decrease with a preset current difference and determines if the photo-voltaic array operates at zone A or zone B based on change of the output voltage before and after the operation to decide the next operation being for load increase or load decrease. It is not necessary for tracking the maximum power with the multiplier to estimate the output power of the photo-voltaic array. Therefore, the circuit for tracking the maximum power of the photo-voltaic array is capable of being simplified and joined to the pulse width modulation circuit to form an integrated circuit with a function of tracking the maximum power. | 02-24-2011 |
20110156685 | CONSTANT TIME BUCK-BOOST SWITCHING REGULATOR AND CONTROL CIRCUIT AND METHOD FOR THE SAME - The present invention discloses a constant time buck-boost switching regulator, and a control circuit and a method for controlling the buck-boost switching regulator. The buck-boost switching regulator includes an inductor, a first and a second power switches coupled to a first end and a second end of the inductor respectively, and a first and a second power devices coupled to the first end and the second end of the inductor respectively, the first power switch being coupled between the first end of the inductor and an input voltage, the second power switch being coupled between the second end of the inductor and ground, the first power device being coupled between the first end of the inductor and ground, and the second power device being coupled between the second end of the inductor and an output voltage. The control method comprises: generating only one single constant time; and generating a switch control signal to control the first and second power switches such that the first and second power switches operate by the same switching period with the same ON-time. | 06-30-2011 |
20110222314 | POWER SUPPLY WITH REDUCED POWER CONSUMPTION - A power supply includes an isolated power converter and a DC/DC converter. The isolated power converter includes a primary winding connected to a primary power stage, a secondary winding to generate a first output voltage, and an auxiliary winding at the primary side to generate a voltage signal proportional to the first output voltage to stabilize the first output voltage. The DC/DC converter converts the first output voltage into a second output voltage for supplying for a load. | 09-15-2011 |
20120105030 | CONTROL CIRCUIT AND METHOD FOR A CURRENT MODE CONTROLLED POWER CONVERTER - A control circuit and method for a current mode controlled power converter to convert an input voltage into an output voltage, dynamically adjust the peak or the valley of a ramp signal depending on either or both of the input voltage and the output voltage. Under different conditions of the input voltage and the output voltage, the current mode controlled power converter can generate stable output voltages with an invariant inductor and an invariant compensation circuit, without sub-harmonic which otherwise may happen. | 05-03-2012 |
20120146602 | CONTROL CIRCUIT AND METHOD FOR A BUCK-BOOST SWITCHING CONVERTER - A control circuit and method for a buck-boost switching converter provides a mode determinative circuit to judge the timing of an operation under buck-boost mode based on the input voltage, the output voltage and the mode reference voltage; meanwhile, the control signal generating circuit is provided to turn off the second switch during the first switch being on, turn on the second switch during the first switch being off, turn off the fourth switch during the third switch being on, turn on the fourth switch during the third switch being off, wherein the duty cycles of the first and third switches are identical, and duty cycles of the second and fourth switches are identical. | 06-14-2012 |
20120235658 | POWER REDUCTION OF A POWER SUPPLY UNIT AT LIGHT LOADING OR NO LOADING - A power supply unit includes a switching power converter responsive to a control signal to switch a power switch thereof to provide an output voltage and an output current for a load. To reduce light-load or no-load power consumption of the power supply unit, the power supply unit repeats a process of stopping switching the power switch and recovering switching the power switch for a period of time once the output voltage decreases to be lower than a reference voltage. | 09-20-2012 |
20120262142 | CONTROL DEVICE FOR BUCK-BOOST CONVERTER - A control device is disclosed, having a signal generating circuit and a mode decision circuit. The signal generating circuit is used to generate a first control signal and a second control signal according to an output voltage of a buck-boost converter. The first control signal is used to conduct a first switch and a second switch of the buck-boost converter. The second control signal is used to conduct a third switch and a fourth switch of the buck-boost converter. When the duty cycle of the first control signal is greater than a first predetermined value and the duty cycle of the second control signal is less than a second predetermined value, the mode decision circuit configures the signal generating circuit to generate the first control signal and the second control signal with substantially the same duty cycle. | 10-18-2012 |
20120293082 | Light emitting device open/short detection circuit - The present invention discloses a light emitting device open/short detection circuit, which is used for detecting at least one light emitting device string open/short. Each light emitting device string has a first end and a second end, wherein the first end is coupled to a voltage supply circuit to supply electrical power to the light emitting devices. The open/short detection circuit includes: an abnormal voltage detection circuit coupled to the light emitting device strings for receiving voltages of the second ends respectively and generating an abnormal voltage detection signal; a voltage setting circuit coupled to the abnormal voltage detection circuit for setting an abnormal reference level; and a determination circuit coupled to the voltage setting circuit. When the abnormal voltage detection signal is equal to or over the abnormal reference level, the determination circuit generates an open/short detection signal for an abnormal condition detected. | 11-22-2012 |
20130170261 | SELF-DISCHARGE CONTROL FOR AN EMI FILTER CAPACITOR - An independent bleeding integrated circuit device is provided to replace the bleeding resistor for an EMI filter capacitor, to establish a discharge path between the two terminals of the EMI filter capacitor when the EMI filter capacitor is disconnected from an AC power source, for discharging the EMI filter capacitor. When the EMI filter capacitor is connected with an AC power source, the discharge path is cut off to avoid power loss. | 07-04-2013 |
20130335038 | BLEEDING CIRCUIT AND METHOD FOR REDUCING POWER CONSUMPTION OF AN EMI FILTER - A bleeding circuit and method for an electromagnetic interference filter detect whether or not an AC power source connected to the electromagnetic interference filter is removed, establish a discharge path for discharging a capacitor of the electromagnetic interference filter once the connected AC power source is removed, and cut off the discharge path during the AC power source is in connection to the electromagnetic interference filter for decreasing power consumption of the electromagnetic interference filter. | 12-19-2013 |