Patent application number | Description | Published |
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 |