Patent classifications
H03M3/34
Input device receiver with delta-sigma modulator
A processing system, and associated input device and method are disclosed suitable for reducing a receiver size within the input device. The processing system comprises a delta-sigma modulator comprising one or more input nodes configured to receive a signal based on a sensor signal received from at least a first sensor electrode of the plurality of sensor electrodes. The delta-sigma modulator further comprises an integrator coupled with the one or more input nodes and configured to produce an integration signal, a quantizer coupled with an output of the integrator and configured to quantize the integration signal, and a feedback digital-to-analog converter (DAC) controlled based by the quantizer. The processing system further comprises a digital filter coupled with an output of the delta-sigma modulator and configured to mitigate a quantization noise of the quantizer.
Fully capacitive coupled input choppers
A method of differential signal transfer from a differential input Vinp and Vinn having a common mode input voltage that can be higher than the power supply voltage by providing an input chopper having first through fourth chopper transistors, each having a source, a drain and a gate, the input chopper having Vinp and Vinn as a differential input, providing an output chopper, capacitively coupling a differential output Voutp and Voutn of the input chopper to a differential input of the output chopper, capacitively coupling a clock to the input chopper and coupling the clock to the output chopper, the clock having a first phase and a second phase opposite from the first phase, the first phase being coupled to the gates of the first and second transistors and the second phase being coupled to the gates of the third and fourth transistors, and providing protection of the gates of the first through fourth transistors from excessive voltages. Various embodiments are disclosed.
Low power analog to digital converter
Described is an analog to digital converter (ADC) which comprises: a sigma-delta modulator to receive an analog signal, the sigma-delta modulator operable to perform chopping to cancel common-mode noise; and one or more counters coupled to the sigma-delta modulator to generate a digital code representative of the analog signal.
Segmented digital-to-analog converter
Disclosed examples include a segmented DAC circuit, including an R-2R resistor DAC to convert a first subword to a first analog output signal, an interpolation DAC to offset the first analog output signal based on an N-bit digital interpolation code signal to provide the analog output signal, and a Sigma Delta modulator to modulate a modulator code to provide the N-bit digital interpolation code signal that represents a value of second and third subwords.
INPUT DEVICE RECEIVER WITH DELTA-SIGMA MODULATOR
A processing system, and associated input device and method are disclosed suitable for reducing a receiver size within the input device. The processing system comprises a delta-sigma modulator comprising one or more input nodes configured to receive a signal based on a sensor signal received from at least a first sensor electrode of the plurality of sensor electrodes. The delta-sigma modulator further comprises an integrator coupled with the one or more input nodes and configured to produce an integration signal, a quantizer coupled with an output of the integrator and configured to quantize the integration signal, and a feedback digital-to-analog converter (DAC) controlled based by the quantizer. The processing system further comprises a digital filter coupled with an output of the delta-sigma modulator and configured to mitigate a quantization noise of the quantizer.
Delta sigma modulator with dynamic error cancellation
The disclosure provides a delta sigma modulator that includes a first input port and a second input port. These ports receive a differential input signal. A DAC is coupled to the first input port and the second input port, and receives a differential feedback signal and a plurality of selection signals. A loop filter generates a differential filtered signal in response to a differential error signal. The differential error signal is proportional to a difference in the differential input signal and the differential feedback signal. A quantizer generates a quantized output signal in response to the differential filtered signal. A modified DWA block coupled between the quantizer and the DAC, generates the plurality of selection signals in response to a chop clock, a regular clock, the quantized output signal and a plurality of selection index signals. A selection index signal is dependent on previously generated plurality of selection signals.
Delta Sigma Modulator with Dynamic Error Cancellation
The disclosure provides a delta sigma modulator that includes a first input port and a second input port. These ports receive a differential input signal. A DAC is coupled to the first input port and the second input port, and receives a differential feedback signal and a plurality of selection signals. A loop filter generates a differential filtered signal in response to a differential error signal. The differential error signal is proportional to a difference in the differential input signal and the differential feedback signal. A quantizer generates a quantized output signal in response to the differential filtered signal. A modified DWA block coupled between the quantizer and the DAC, generates the plurality of selection signals in response to a chop clock, a regular clock, the quantized output signal and a plurality of selection index signals. A selection index signal is dependent on previously generated plurality of selection signals.
Chopper stabilized sigma delta ADC
A ADC includes a forward path, a feedback path, and offset compensation circuitry. The forward path is configured to convert an analog input signal to a digital output signal and includes analog chopper circuitry configured to shift the analog input signal to a chopper frequency to generate a chopped analog signal. The feedback path includes a DAC configured to convert a digital offset compensation signal configured to compensate for offset error in the analog input signal to an analog feedback signal that is subtracted from a forward path signal. The offset compensation circuitry is configured to accumulate a chopped digital signal from the forward path to generate a digital offset error signal; add the digital offset error signal to the digital output signal to generate the digital offset compensation signal; and provide the digital offset compensation signal to the DAC.
Delta sigma modulator with dynamic error cancellation
The disclosure provides a delta sigma modulator that includes a first input port and a second input port. These ports receive a differential input signal. A DAC is coupled to the first input port and the second input port, and receives a differential feedback signal and a plurality of selection signals. A loop filter generates a differential filtered signal in response to a differential error signal. The differential error signal is proportional to a difference in the differential input signal and the differential feedback signal. A quantizer generates a quantized output signal in response to the differential filtered signal. A modified DWA block coupled between the quantizer and the DAC, generates the plurality of selection signals in response to a chop clock, a regular clock, the quantized output signal and a plurality of selection index signals. A selection index signal is dependent on previously generated plurality of selection signals.
DELTA SIGMA MODULATOR WITH DYNAMIC ERROR CANCELLATION
The disclosure provides a delta sigma modulator that includes a first input port and a second input port. These ports receive a differential input signal. A DAC is coupled to the first input port and the second input port, and receives a differential feedback signal and a plurality of selection signals. A loop filter generates a differential filtered signal in response to a differential error signal. The differential error signal is proportional to a difference in the differential input signal and the differential feedback signal. A quantizer generates a quantized output signal in response to the differential filtered signal. A modified DWA block coupled between the quantizer and the DAC, generates the plurality of selection signals in response to a chop clock, a regular clock, the quantized output signal and a plurality of selection index signals. A selection index signal is dependent on previously generated plurality of selection signals.