Abstract: A mixed signal correlator utilizes coherent detection within a capacitance measurement application. In some applications, the mixed signal correlator is used to measure capacitance of a touch screen display. An external capacitor whose capacitance is measured is kept small for improved sensitivity and can be used for a variety of applications having varied integration periods for measurement. The external capacitor is kept small and can be used for varied applications by adjusting the output voltage within a range that is less than the supply voltage, and maintaining a count of the adjustments to later reconstruct an actual output voltage for the integration period. An output is a weighted sum of an analog integrator output and a digital counter output.

Abstract: An analog front end circuit utilizes coherent detection within a capacitance measurement application. The analog front end circuit uses coherent detection to measure capacitance of a touch screen display. An analog excitation signal is modulated by a capacitor to be measured. The modulated signal is synchronously demodulated using a correlator, which includes an integrated mixing and integration circuit. The correlator includes a programmable impedance element that generates a time-varying conductance according to a controlling digitized waveform.

Abstract: A mixed signal correlator utilizes coherent detection within a capacitance measurement application. In some applications, the mixed signal correlator is used to measure capacitance of a touch screen display. An external capacitor whose capacitance is measured is kept small for improved sensitivity and can be used for a variety of applications having varied integration periods for measurement. The external capacitor is kept small and can be used for varied applications by adjusting the output voltage within a range that is less than the supply voltage, and maintaining a count of the adjustments to later reconstruct an actual output voltage for the integration period. An output is a weighted sum of an analog integrator output and a digital counter output.

Abstract: Capacitance sensing circuits, systems and method can include sample and hold (S/H) circuits that can retain analog values for one set of capacitance sensors, and sequentially convert such analog values into digital values while analog values for another set of capacitance sensors values are generated.

Abstract: A touch panel sensor system that can dynamically measure noise and automatically switch to a frequency with minimal noise is described. The touch panel sensor system includes a sensor configured to detect a change in capacitance associated with a touch upon a touch panel. The system also includes a drive module configured to generate a drive signal having a first waveform characteristic (e.g., signal having a periodic waveform characteristic) during a first phase (e.g., sensor phase) and a second drive signal having a second waveform characteristic (e.g., constant voltage signal) during a second phase (e.g., noise detection phase). The first and second drive signals are configured to drive the sensor. The system also includes a measuring module coupled to the sensor that is configured to measure noise having the first waveform characteristic (e.g., periodic waveform characteristic) during the second phase.

Abstract: A touch panel sensor system for increasing the dynamic range of the system is disclosed. The touch panel sensor system comprises a sensor driver module for driving one or more sensors of a touchscreen and an offset cancellation driver module for driving an offset cancellation module. The signals generated by the sensors and the offset cancellation module are coupled to a measuring module at a node (N1). The signal generated by the offset cancellation drivers can be adjusted so that the waveform characteristics (e.g., amplitude and phase) of the signal generated by the offset cancellation drivers in combination with the offset cancellation module can at least partially cancel parasitic and sensor capacitances (Cs) of the sensors of the touch panel. A measuring module may then detect a touch event capacitance (C?) at the node (N1).

Abstract: A complex filter includes an I channel having a first I channel output and a second I channel output and a Q channel having a first Q channel output and a second Q channel output. The second I channel output is input to the Q channel through a first passive network and wherein the second Q channel output is input to the I channel through a second passive network.

Abstract: Calibrating a filter is disclosed. The filter is reconfigured as an oscillator during calibration. Switches and/or other implementations of reconfiguring a filter are used to reconfigure the negative feedback loop of the filter to a positive feedback loop. The oscillation parameters are then measured to adjust the components of the filter to achieve an oscillation that corresponds to a desired filter characteristic.

Abstract: A transceiver used in a communications system includes a transmitter having a transmit input that is split into a transmit I component and a transmit Q component; a receiver having a receive input that is split into a receive I component and a receive Q component; a switching network configured to input the transmit I component, the transmit Q component, the receive I component and the receive Q component; and to output a sampled sequence; an analog to digital converter configured to receive the sampled sequence and to output a digitized data stream; and a digital signal processor configured to receive the digitized data stream and process the digitized data stream.

Abstract: A system and method are disclosed for configuring a frequency synthesizer to generate a frequency. Configuring a frequency synthesizer to generate a frequency includes transferring channel information that identifies the frequency to be generated from an external processor to the frequency synthesizer; generating a plurality of synthesizer configuration parameters based on the channel information; and configuring the frequency synthesizer using the plurality of synthesizer configuration parameters. Additionally, the frequency synthesizer configuration parameters can be generated using an iterative process with seed values.

Abstract: A CMOS image sensor circuit having a distributed amplifier is disclosed. The CMOS image sensor circuit is constructed using a photo sensor that converts light intensity to into voltage, a reset transistor to charge the photo sensor, and a distributed amplifier to detect and read out the voltage value created by the photo sensor. The distributed amplifier is distributed in the sense that portions of the amplifier circuitry reside within individual pixel circuits that form a CMOS image sensor array. The remainder of the amplifier resides in a column read out circuit that is at the bottom of the CMOS image sensor array.

Abstract: According to the principles of this invention, an improved CMOS image sensor is disclosed. The improved CMOS image sensor comprises a pair of controllable column and row decoders, a signal conditioning circuit and a pixel processor in addition to an array of photo sensors. With the pair of controllable column and row decoders, photo sensors can selectively and dynamically accessed to improve signal throughput for applications that do not require the full set of signals from the array of photo sensors. The digitized signals from the selected photo sensors can be processed in the pixel processor for auto focus, pixel signals decimation and interpolation, data conversation and compression. Consequently, the design complexity of an overall imaging system using the disclosed CMOS image sensor is considerably reduced and the performance thereof is substantially increased.

Abstract: A complex filter includes an I channel having a first I channel output and a second I channel output and a Q channel having a first Q channel output and a second Q channel output. The second I channel output is input to the Q channel through a first passive network and wherein the second Q channel output is input to the I channel through a second passive network.

Abstract: A CMOS image sensor circuit having a distributed amplifier is disclosed. The CMOS image sensor circuit is constructed using a photo sensor that converts light intensity to into voltage, a reset transistor to charge the photo sensor, and a distributed amplifier to detect and read out the voltage value created by the photo sensor. The distributed amplifier is distributed in the sense that portions of the amplifier circuitry reside within individual pixel circuits that form a CMOS image sensor array. The remainder of the amplifier resides in a column read out circuit that is at the bottom of the CMOS image sensor array.

Abstract: A CMOS image sensor circuit having a distributed amplifier is disclosed. The CMOS image sensor circuit is constructed using a photo sensor that converts light intensity to into voltage, a reset transistor to charge the photo sensor, and a distributed amplifier to detect and read out the voltage value created by the photo sensor. The distributed amplifier is distributed in the sense that portions of the amplifier circuitry reside within individual pixel circuits that form a CMOS image sensor array. The remainder of the amplifier resides in a column read out circuit that is at the bottom of the CMOS image sensor array.