Patent application number | Description | Published |
20120217981 | CIRCUITS, DEVICES AND METHODS HAVING PIPELINED CAPACITANCE SENSING - 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. | 08-30-2012 |
20120218020 | CALIBRATION FOR MIXED-SIGNAL INTEGRATOR ARCHITECTURE - 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. | 08-30-2012 |
20120218223 | CONTINUOUS TIME CORRELATOR ARCHITECTURE - 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. | 08-30-2012 |
20120274404 | MIXED-SIGNAL INTEGRATOR ARCHITECTURE - 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. | 11-01-2012 |
20130162586 | CAPACITIVE TOUCH SENSE ARCHITECTURE - 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 a discrete mixer and a discrete integrator. The excitation signal is also input to the mixer such that the modulated signal is multiplied by the excitation signal. The excitation signal is an analog signal having a sine wave function or other waveform. | 06-27-2013 |
20140152328 | CONTINUOUS TIME CORRELATOR ARCHITECTURE - A system includes a signal generator and a correlator. The signal generator outputs a first signal to a first end of a capacitance to be measured. The correlator is connected to an output of the signal generator that outputs the first signal and to a second end of the capacitance. The correlator receives the first signal from the output of the signal generator and receives a second signal from the second end of the capacitance. The correlator correlates the first signal and the second signal and generates an output signal based on a correlation between the first signal and the second signal. The output signal is proportional to a capacitance value of the capacitance. | 06-05-2014 |
20150048851 | CAPACITIVE TOUCH SENSE ARCHITECTURE HAVING A CORRELATOR FOR DEMODULATING A MEASURED CAPACITANCE FROM AN EXCITATION SIGNAL - 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 a discrete mixer and a discrete integrator. The excitation signal is also input to the mixer such that the modulated signal is multiplied by the excitation signal. The excitation signal is an analog signal having a sine wave function or other waveform. | 02-19-2015 |
20150324061 | BACKGROUND NOISE MEASUREMENT AND FREQUENCY SELECTION IN TOUCH PANEL SENSOR SYSTEMS - 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. | 11-12-2015 |