Abstract: In one embodiment, a method for monitoring a heartbeat includes receiving a heartbeat signal, the heartbeat signal including heartbeat cycles. The method also includes determining a region of interest (ROI) of the heartbeat cycles based on an identifying feature of each heartbeat cycle of the heartbeat cycles. The ROI includes a first portion of a period of a first heartbeat cycle. The method also includes sampling the first portion of the heartbeat cycle within the ROI at a first sampling rate and sampling a second portion of the heartbeat cycle outside of the ROI at a second sampling rate less than the first sample rate.

Abstract: An optical detector includes a first set of one or more photodiodes configured to generate a first photocurrent according to a first spectral response function of an incident light, a second set of one or more photodiodes configured to generate a second photocurrent according to a second spectral response function of the incident light, and a third set of one or more photodiodes configured to generate a third photocurrent according to a third spectral response function of the incident light. The optical detector further includes a module configured to output an indication of the intensity of the incident light according to a fourth spectral response function based on each of the first photocurrent, the second photocurrent, and the third photocurrent.

Abstract: In various embodiments a device is provided. The device includes an integrated circuit that includes one or more photodetector elements and a blocking structure monolithically integrated with the one or more photodetector elements. The one or more photodetector elements are arranged relative to the blocking structure such that electrical currents provided by the one or more photodetector elements in response to electromagnetic waves received by the one or more photodetector elements are indicative of a direction to a source providing the electromagnetic waves.

Abstract: An optical detector includes a first set of one or more photodiodes configured to generate a first photocurrent according to a first spectral response function of an incident light, a second set of one or more photodiodes configured to generate a second photocurrent according to a second spectral response function of the incident light, and a third set of one or more photodiodes configured to generate a third photocurrent according to a third spectral response function of the incident light. The optical detector further includes a module configured to output an indication of the intensity of the incident light according to a fourth spectral response function based on each of the first photocurrent, the second photocurrent, and the third photocurrent.

Abstract: Some embodiments of the invention relate to a DC offset correction circuit comprising a feedback loop having a DAC controlled by a reconfigurable ADC, which determines (e.g., tracks) the mean value of a modulated input signal. The circuit operates according to two phase process. In a first “pre-modulation” tracking phase, an input signal is tracked by the ADC, which is configured to output the input signal's mean value as a digital code equivalent to the input mean value. The output of the ADC is provided to a DAC, which provides an analog representation of the mean value to an adder that subtracts the mean value from the modulated input signal to generate a bipolar adjusted input signal. In a second “modulation” phase, the estimated mean value is held constant, so that the bipolar adjusted input signal may be provided to an activated modulation circuit for improved system performance.

Abstract: In various embodiments a device is provided. The device includes an integrated circuit that includes one or more photodetector elements and a blocking structure monolithically integrated with the one or more photodetector elements. The one or more photodetector elements are arranged relative to the blocking structure such that electrical currents provided by the one or more photodetector elements in response to electromagnetic waves received by the one or more photodetector elements are indicative of a direction to a source providing the electromagnetic waves.

Abstract: This application describes a system for minimizing the common mode voltage drift at the input of a fully differential amplifier. An impedance component is coupled to the inputs and outputs of the differential amplifier. The impedance component optimizes the common mode resistance or impedance to ground without significantly affecting the differential impedance, matches the input common mode voltage to the output common mode voltage and reduces the input common mode voltage drift in presence of leakage currents.

Abstract: Some embodiments of the invention a circuit configured to apply a time domain processing sequence to a modulated input signal to estimate a mean value of the modulated input signal and to subtract the estimated mean value from the modulated input signal, thereby removing the DC offset from the input signal. In one particular embodiment, the time domain processing sequence is based on integration and differentiation of a demodulated output signal. In such an embodiment, a circuit is configured to integrate a demodulated signal to generate an integrated signal having a triangular shaped output signal. The circuit then measures the slopes of the integrated signal, by differentiation of the triangular shaped integrated signal, and generates an appropriate DC offset correction signal based upon the measured slopes. The DC offset correction signal may be added on top of the actual input signal to cancel the unwanted DC offset component.

Abstract: This application describes a system for minimizing the common mode voltage drift at the input of a fully differential amplifier. An impedance component is coupled to the inputs and outputs of the differential amplifier. The impedance component optimizes the common mode resistance or impedance to ground without significantly affecting the differential impedance, matches the input common mode voltage to the output common mode voltage and reduces the input common mode voltage drift in presence of leakage currents.

Abstract: Some embodiments of the invention a circuit configured to apply a time domain processing sequence to a modulated input signal to estimate a mean value of the modulated input signal and to subtract the estimated mean value from the modulated input signal, thereby removing the DC offset from the input signal. In one particular embodiment, the time domain processing sequence is based on integration and differentiation of a demodulated output signal. In such an embodiment, a circuit is configured to integrate a demodulated signal to generate an integrated signal having a triangular shaped output signal. The circuit then measures the slopes of the integrated signal, by differentiation of the triangular shaped integrated signal, and generates an appropriate DC offset correction signal based upon the measured slopes. The DC offset correction signal may be added on top of the actual input signal to cancel the unwanted DC offset component.

Abstract: Some embodiments of the invention relate to a DC offset correction circuit comprising a feedback loop having a DAC controlled by a reconfigurable ADC, which determines (e.g., tracks) the mean value of a modulated input signal. The circuit operates according to two phase process. In a first “pre-modulation” tracking phase, an input signal is tracked by the ADC, which is configured to output the input signal's mean value as a digital code equivalent to the input mean value. The output of the ADC is provided to a DAC, which provides an analog representation of the mean value to an adder that subtracts the mean value from the modulated input signal to generate a bipolar adjusted input signal. In a second “modulation” phase, the estimated mean value is held constant, so that the bipolar adjusted input signal may be provided to an activated modulation circuit for improved system performance.