Abstract: A system for measuring a gas concentration, the system including: a first oscillator including a first surface for placement in a sampling location, wherein the first oscillator oscillates at a frequency greater than 20,000 Hz but less than 300,000,000 Hz; a first counter to accumulate a count of oscillations of the first oscillator; and a comparator to calculate a difference between the accumulated counts of the first oscillator and a reference, wherein the difference calculated by the comparator is sampled at a frequency of less than 100 Hz.

Abstract: A system for stabilizing sensor readings. The system includes a processor; a memory communicatively coupled to the processor; a receiver to receive from a sensing device, a measurement and an environmental parameter. The system also includes a machine learning engine executed on the processor wherein the machine learning engine receives, as inputs: the environmental parameters; the measurement; and control parameters calculated based on control measurements made at time points before and after the measurement.

Abstract: A system for stabilizing sensor readings. The system includes a processor; a memory communicatively coupled to the processor; a receiver to receive from a sensing device, a measurement and an environmental parameter. The system also includes a machine learning engine executed on the processor wherein the machine learning engine receives, as inputs: the environmental parameters; the measurement; and control parameters calculated based on control measurements made at time points before and after the measurement.

Abstract: This document describes a method of determining an extent of mold behind a surface. The method includes moving a gas sensor lateral to the surface. The gas sensor includes an oscillating gas-interacting surface. The method includes measuring gas concentrations at multiple points along the surface. The method also includes displaying a heat map in a display. The heat map shows gas concentrations at multiple points along the surface.

Abstract: This document describes a method of determining an extent of mold behind a surface. The method includes moving a gas sensor lateral to the surface. The method also includes measuring gas concentrations at multiple points along the surface. Also described is a system for mapping gas concentrations at a surface. The system includes a drone with a gas sensor and a transmitter. The system also includes a receiver in communication with the drone. The receiver receives transmissions from the drone which include gas measurements, and distances between the gas sensor and the surface.

Abstract: A system for measuring a gas concentration, the system including: a first oscillator including a first surface for placement in a sampling location, wherein the first oscillator oscillates at a frequency greater than 20,000 Hz but less than 300,000,000 Hz; a first counter to accumulate a count of oscillations of the first oscillator; and a comparator to calculate a difference between the accumulated counts of the first oscillator and a reference, wherein the difference calculated by the comparator is sampled at a frequency of less than 100 Hz.

Abstract: An integrated circuit (IC) includes first and second circuits. The first circuit is manufactured using a process, has an input and an output, and has a first nonlinearity. The second circuit is manufactured using the process, has a first terminal connected to the output of the first circuit and a second terminal connected to the input of the first circuit, and has a second nonlinearity. The second nonlinearity (i) is equal and opposite to the first nonlinearity and (ii) cancels the first nonlinearity.

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 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.

Abstract: Operating range of R-2R ladders for digital to analog converters (DACs) is improved by increasing resistance in series with a termination switch in a termination leg to avoid transistor saturation for increasing DAC resolution, increasing reference voltage range, or other application. The switched R-2R ladder circuit is modified to compensate for increasing resistance to maintain proper resistor matching for generation of the appropriate range of analog output voltages for a digital input signal.

Abstract: Operating range of R-2R ladders for digital to analog converters (DACs) is improved by increasing resistance in series with a termination switch in a termination leg to avoid transistor saturation for increasing DAC resolution, increasing reference voltage range, or other application. The switched R-2R ladder circuit is modified to compensate for increasing resistance to maintain proper resistor matching for generation of the appropriate range of analog output voltages for a digital input signal.

Abstract: Asynchronous and synchronous deglitch controllers controlling switches of sample and hold circuits for deglitching digital to analog converters. Asynchronous and synchronous deglitch controllers detect transitions in the state of the digital input code to trigger or allow a one shot pulse to cause sample and hold circuits to go into hold mode for the period of the one shot pulse. Secondary glitch cancellation circuitry models the environment of the sample and hold circuit to emulate secondary glitch impulse generation. A differential amplifier substantially cancels secondary glitches related to the parasitic charges generated by the switching of the sample and hold circuit.

Abstract: A varying power supply range, that can exceed the breakdown voltage of switches within a DAC, is used to generate positive and negative generated OFF voltages substantially fixed and less than the breakdown voltage to accommodate a wide range of analog reference voltages and power supply voltages. The digital input signal having digital input levels is received by a TTL/CMOS input receiver and level shifted to logic levels having the positive and negative generate voltage levels. A circuit matches switch resistance and forms positive and negative switch ON voltage levels from the voltage levels of the input positive and negative analog reference levels. Switch drivers properly drive control terminals of the switches with appropriate voltage levels avoiding switch breakdown in response to the digital input signal.

Abstract: Operating range of R-2R ladders for digital to analog converters (DACs) is improved by increasing resistance in series with a termination switch in a termination leg to avoid transistor saturation for increasing DAC resolution, increasing reference voltage range, or other application. The switched R-2R ladder circuit is modified to compensate for increasing resistance to maintain proper resistor matching for generation of the appropriate range of analog output voltages for a digital input signal.

Abstract: Buffers having an output pull-up transistor controlled by the input signal, an output pull-down transistor and a pull-down transistor control circuit. A current source provides a current that is divided between the pull-up transistor and the pull-down transistor control circuit to maintain the desired output voltage. A boost capacitor is coupled between the output and the pull-down transistor control circuit to provide good dynamic response to the circuit even in the presence of substantial capacitive loads on the output. In addition a second capacitor is coupled between the pull-down transistor control circuit and a fixed voltage to provide a low frequency pole internal to the circuit. The connection of the boost capacitor to the pull-down transistor control circuit and the connection of the second capacitor to the pull-down transistor control circuit are separated by a substantial resistance, allowing the effect of each capacitor to be substantially independent of each other.

Abstract: The present invention provides a switch circuit having a switch and a first body grabbing circuit. The switch includes a first transistor and a second transistor. The first transistor has a body and is coupled to the second transistor in parallel to form a common source and a common drain. The common source defines an input node and the common drain defines an output node. The first body grabbing circuit is coupled to the body of the first transistor. The first body grabbing circuit is arranged to couple the body of the first transistor to the input node when the first and second transistors receive a turn-on voltage signal such that a body effect is eliminated in the first transistor.

Abstract: Field effect transistor voltage generator circuitry, particularly useful with CMOS operational amplifiers, uses a first branch circuit which contains transistors which mirrors transistors of the amplifier and uses a second branch circuit which functions to bias the first branch circuit. At least one feedback path exists from the first branch circuit to the second branch circuit to help maximize the dynamic range of the amplifier by generating reference potentials which are as far apart as is practical.

Abstract: A single stage high performance operational transconductance amplifier consists of a pair of p-channel load field effect transistors, a pair of n-channel type cascode field effect transistors, a pair of n-channel differential field effect transistors and an n-channel current source field effect transistor. This amplifier has improved performance in terms of noise and power supply rejection as compared to conventional CMOS amplifiers.