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Dazhi Wei, Austin US

Dazhi Wei, Austin, TX US

Patent application numberDescriptionPublished
20090085535DC/DC BOOST CONVERTER WITH PULSE SKIPPING CIRCUITRY - A DC to DC boost converter circuit receives a DC input voltage and converts it to a DC output voltage at a different voltage level than the DC input voltage. The DC to DC boost converter includes a switching power converter for receiving the input voltage on an input and converting the input voltage to an output as the DC output voltage in response to pulse control signals. A switching controller generates the pulse control signals during a switching cycle. The switching controller further includes pulse skipping circuitry for generating a pulse width modulated signal to the switching power converter. A pulse width of the pulse width modulated signal is decreased responsive to a voltage level of an output voltage of the DC to DC boost converter being less than a control saw tooth waveform and the pulses width of the pulse width modulated signal is increased responsive to the voltage level of the output voltage of the DC to DC boost converter being greater than the control saw tooth waveform.04-02-2009
20090085619POWER SUPPLY VOLTAGE MONITORS - The single chip microcontroller unit includes a processing unit having normal power mode of operation and a low power mode of operation. Analog circuitry and digital circuitry are connected to the processing unit. Monitoring circuitry determines if a chip supply voltage level exceeds a threshold level necessary to maintain operation of the digital circuitry.04-02-2009
20090086517DC/DC BOOST CONVERTER WITH RESISTORLESS CURRENT SENSING - A DC to DC boost converter circuit receives a DC input voltage and converts it to a DC output voltage at a different voltage level than the DC input voltage. The DC to DC boost converter includes a switching power converter for receiving the input voltage on an input and converting the input voltage to an output as the DC output voltage in response to pulse control signals. A switching controller generates the pulse control signals during a switching cycle. Current sensing circuitry limits a current passing through the switching power converter. The current sensing circuitry generates an overload signal when the current exceeds a reference value. The current sensing circuitry sensing the current with a current sensing resistor having a size of at least approximately 500 ohms.04-02-2009
20090089599POWER SUPPLY SYSTEM FOR LOW POWER MCU - A microcontroller includes a processing unit having a processing unit having normal power mode of operation and a low power mode of operation. The processing unit further having digital circuitry connected to the processing unit having a plurality of logic circuits associated therewith for processing digital values. A plurality of retention flip-flops are associated with the digital circuitry for storing a logical state of at least one or more of the logic circuits within the digital circuitry when the processing unit enters the low power mode of operation. The plurality of retention flip flops include a first type of transistors for operating in both the low and high power modes of operation and a second type of transistors for operation only in the normal mode of operation and wherein substantially the remainder of the digital circuitry in the processing unit comprises the second type of transistors.04-02-2009
20090089605POWER SUPPLY VOLTAGE MONITORS - The single chip microcontroller unit includes a processing unit having normal power mode of operation and a low power mode of operation. Analog circuitry and digital circuitry are connected to the processing unit. A power management unit controls power operations of the processing unit, the analog circuitry and the digital circuitry. Power monitoring circuitry provides power control signals to the power management unit. The power monitoring circuitry further includes a system voltage monitoring circuit for generating a system voltage control signal responsive to a system voltage level with respect to a predetermined level. The power monitoring circuitry also includes a supply monitoring circuit for determining if a chip supply voltage level exceeds a threshold level.04-02-2009
20100156175DC/DC BOOST CONVERTER WITH BYPASS FEATURE - An integrated circuit package includes a DC/DC boost converter for providing an output voltage at a program level to associated components of the integrated circuit package. The DC/DC boost converter includes a first mode of operation wherein the DC/DC boost converter is enabled responsive to an input battery voltage falling below a programmed level of the output voltage. The DC/DC boost converter also includes a second mode of operation wherein the DC/DC boost converter is disabled responsive to the input battery voltage being above the programmed level of the output voltage.06-24-2010
20110156839CAPACITIVE SENSOR WITH VARIABLE CORNER FREQUENCY FILTER - A system and method for configuring a variable filter in a capacitive sensing circuit are provided. In one example, the circuit includes first and second circuitry and control logic. The first circuitry is configured to provide a variable resistance path that is coupled to an external capacitor that is to be sensed by the capacitive sensing circuit. The second circuitry controls actuation of the first circuitry and is responsive to a voltage change that occurs when a charge level of the external capacitor is altered. The second circuitry actuates the first circuitry when the voltage change causes a voltage supplied to the second circuitry to pass a predefined threshold. The control logic receives input identifying a desired corner frequency, determines a resistance setting for the first circuitry corresponding to the corner frequency, and applies the resistance setting to the first circuitry to configure the first circuitry at the corner frequency.06-30-2011
20110157077CAPACITIVE SENSOR SYSTEM WITH NOISE REDUCTION - A system for reducing noise when detecting the capacitance value of a capacitor in a touch display that operates in a potentially noisy environment. A capacitance sensor is provided for determining the size of the capacitor in the touch screen display and includes a charging circuit that charges the capacitor and a discharge circuit that resets the charge of the capacitor to substantially zero. A control circuit controls the capacitance sensor and the operation of the charge and discharge circuits in accordance with a predetermined charging/discharging algorithm to resolve the value of the capacitor and output such value in a sampling operation. The operation of the control circuit and the charging/discharging algorithm is subject to errors as a function of the noisy environment, which errors will be reflected in the output value. A noise reduction circuit is provided to modify the operation of the control circuit to reduce noise.06-30-2011

Patent applications by Dazhi Wei, Austin, TX US