Systems and methods for interrogating sensing systems utilising bursts of samples. Bursts of samples correspond to optical pulses returning from optical sensors, where pulses are spaced at a period significantly longer than the pulse width, giving irregular sample spacing. The interrogation system and method processes the irregular busts of samples to recover phase information from received signals.

Systems and methods for interrogating sensing systems utilising bursts of samples. Bursts of samples correspond to optical pulses returning from optical sensors, where pulses are spaced at a period significantly longer than the pulse width, giving irregular sample spacing. The interrogation system and method processes the irregular busts of samples to recover phase information from received signals.

An exemplary incremental two-step capacitance-to-digital converter (CDC) with a time-domain sigma-delta modulator (TDΔΣM) includes a voltage-controlled oscillator (VCO)-based integrator that can be used in a low-order loop configuration. Example prototypes are disclosed, which when fabricated in 40-nm CMOS technology, provides CDC resolution of 0.29 fF while dissipating only 0.083 nJ per conversion.

Systems and methods for measurement and management are disclosed that provide complex measurements cost-effectively at very high accuracy. These methods and systems in some cases achieve measurement accuracy exceeding the accuracy of the reference standards they rely on, and eliminate expensive and disadvantageous recalibration procedures. The accurate measurements are integrated with management functions, applying the measurement data to meet objectives of the integrated system and workflow goals of its user. The disclosed systems and methods comprise an explicit or expressly represented model both of themselves and of candidate external systems to be measured and managed. The models may be configured and reconfigured by the owner-user through either local or remote means. The system intelligently reconfigures itself to adapt dynamically to the conditions of measurement and the user's and system's goals at each moment. In an embodiment, the system includes high-accuracy and reconfigurable components including a meter or control head adapted for user precision assembly and maintenance that computes and displays or communicates the measurements, displaying measurements in desired units, grouping functions according to ergonomic and cognitive principles based on the activity and workflow of a user in relation to the internal model. The use of models permits the system to compute and provide complex and inferred measurements of ultimate interest to the user, including quantities that cannot be directed measured and only can be determined through reasoning or computation by applying models to raw measurement data. The precision-assembly modular electromechanical design further permits an owner-user to precisely assemble, maintain, modify the apparatus and calibrate the equipment for accuracy.

The present disclosure discloses a band-pass analog-to-digital converter (ADC) using a bidirectional voltage-controlled oscillator (VCO) including a first converter configured to receive an analog input signal and quantize the analog input signal according to a first clock signal to output a first digital signal, a second converter configured to receive the analog input signal and quantize the analog input signal in a time-interleaving manner according to a second clock signal, which has a phase opposite to that of the first clock signal, to output a second digital signal, and a multiplexer configured to receive the first and second digital signals and select one of the two signals in response to the first clock signal to finally output a digital output signal.

An analog counter circuit for use with a digital pixel includes an input; an output; a first inverter connected to the input that produces on a first inverter output a time delayed inverted signal (RP*) from an input signal received at the input; a second inverter connected to the first inverter output that produces a time delayed signal (RP) at a second inverter output from the input signal and that is delayed relative to RP* and a control switch connected between a source voltage and a floating node. The control switch is controlled by the signal RP* on the first inverter output. The analog counter also includes a feedback capacitor connected between the second inverter output and the floating node; an accumulating capacitor that accumulates at least some of a charge that passes through the control switch; and an injection switch connected between the control switch and the accumulating capacitor.

A memristor-based circuit includes a voltage generator that applies a series of voltage pulses to a memristor to progressively change the resistance of the memristor. A comparator: receives an input electrical value; receives an electrical value based on the resistance of the memristor; compares the received values; and, based on the comparison, enables the application of the voltage pulses to the memristor by the voltage generator until a defined condition is satisfied. This circuit can be used to enable the memristor to be programmed to a desired resistance value, such as for use as a non-volatile memory. It can also enable the resistance of one memristor to be replicated to another memristor. By counting the number of applied voltage pulses, the circuit can be used as an encoder or analog-to-digital converter. Other variants of the circuit enable construction of a decoder or digital-to-analog converter, and an authentication circuit.

A memristor-based circuit includes a voltage generator that applies a series of voltage pulses to a memristor to progressively change the resistance of the memristor. A comparator: receives an input electrical value; receives an electrical value based on the resistance of the memristor; compares the received values; and, based on the comparison, enables the application of the voltage pulses to the memristor by the voltage generator until a defined condition is satisfied. This circuit can be used to enable the memristor to be programmed to a desired resistance value, such as for use as a non-volatile memory. It can also enable the resistance of one memristor to be replicated to another memristor. By counting the number of applied voltage pulses, the circuit can be used as an encoder or analog-to-digital converter. Other variants of the circuit enable construction of a decoder or digital-to-analog converter, and an authentication circuit.

An analog-to-digital converter (ADC) includes a first controlled oscillator (CO) for generating at least one phase signal, and wherein the at least one phase signal generates a first output signal of the ADC; and at least one first frequency-controlled resistor (FDR) for receiving the at least one phase signal generated by the first CO, wherein the first CO and the at least one first FDR are coupled together at a first subtraction node of the ADC, and wherein the first subtraction node receives a first input signal.

An oscillator-based sensor interface circuit includes first and second input nodes arranged to receive first and second electrical signals representative of an electrical quantity, respectively; an analog filter; a first oscillator arranged to receive a first oscillator input signal and a second oscillator different from the first oscillator and arranged to receive a second oscillator input signal; a comparator arranged to compare signals coming from the first and second oscillators; a first feedback element arranged to receive a representation of the digital comparator output signal and to convert the representation into a first feedback signal to be applied to the oscillation means; a digital filter arranged to yield an output signal, being an filtered version of the digital comparator output signal; a second feedback element arranged to receive the output signal and to convert the output signal into a second feedback signal.