Abstract: Systems, devices, and methods related to hybrid basis function, neural network-based digital predistortion (DPD) are provided. An example apparatus for a radio frequency (RF) transceiver includes a digital predistortion (DPD) actuator to receive an input signal associated with a nonlinear component of the RF transceiver and output a predistorted signal. The DPD actuator includes a basis-function-based actuator to perform a first DPD operation using a set of basis functions associated with a first nonlinear characteristic of the nonlinear component. The DPD actuator further includes a neural network-based actuator to perform a second DPD operation using a first neural network associated with a second nonlinear characteristic of the nonlinear component. The predistorted signal is based on a first output signal of the basis-function-based actuator and a second output signal of the neural network-based actuator.

Abstract: Herein disclosed are multiple embodiments of a signal-processing circuit that may be utilized in various circuits, including conversion circuitry. The signal-processing circuit may receive an input and produce charges on multiple different capacitors during different phases of operation based on the input. The charges stored on two or more of the multiple different capacitors may be utilized for producing an output of the signal-processing circuit, such as by combing the charges stored on two or more of the multiple different capacitors. Utilizing the charges on the multiple different capacitors may provide for a high level of accuracy and robustness to variations of environmental factors, and/or a low noise level and power consumption when producing the output.

Abstract: Presented are systems and methods for automatically decoding and demodulating radio signals in a communication network. Embodiments utilize a one-dimensional (1D) convolutional neural network (CNN) as the key architecture of a decoder that utilizes one or more 1D convolution windows to perform convolution operations on to-be-decoded or demodulated input signals received by the communication network. In embodiments, this may be achieved by receiving, at a CNN correlator implemented in a decoder, an input signal that comprises unknown data and applying to the input signal, in the discrete time domain, a convolution to obtain a CNN correlator output to which an activation may be applied to decode the input signal and output the decoded signal.

Abstract: A current sensor circuit comprises multiple resistive circuit elements of different values of electrical resistance arranged between at least one input terminal of the current sensor circuit and an output terminal; a first plurality of switching circuits coupled between the input terminal and the resistive circuit elements, wherein each switching circuit of the first plurality of switching circuits includes a pair of transistors connected in series; at least one drive amplifier including an output and an input connected to the output terminal; and a second plurality of switching circuits, each switching circuit including a first switch terminal coupled to the at least one drive amplifier output and a second switch terminal coupled to a common connection of a pair of transistors of the first plurality of switching circuits.

Abstract: According to one example configuration, an apparatus enhances functionality of a mobile communication device. The apparatus includes an encasement in which to retain the mobile communication device and supplemental circuitry. The supplemental circuitry is operable to: i) control an optical transmitter in the supplemental circuitry to irradiate matter under test, ii) monitor attributes of an optical signal reflected off the matter under test and received by the optical receiver; and iii) communicate the attributes of the optical signal from the supplemental circuitry to the mobile communication device over a communication link. The supplemental circuitry optionally includes multiple electrodes to further monitor attributes of the matter under test.

Abstract: An example transconductance circuit includes a first portion that includes a first degeneration transistor, configured to receive a first input voltage, and a second portion that includes a second degeneration transistor, coupled to the first degeneration transistor and configured to receive a second input voltage. The first portion further includes a first input transistor, coupled to the first degeneration transistor and configured to provide a first output current, while the second portion further includes a second input transistor, coupled to the second degeneration transistor and configured to provide a second output current. Such a transconductance circuit may be used as an input stage capable of reliably operating within drain-source breakdown voltage of the transistors employed therein even in absence of any other protection devices, and may be significantly faster, consume lower power, and occupy smaller die area compared to conventional transconductance circuits.

Abstract: A switching converter circuit comprises an inductive circuit element; a driver switching circuit configured to provide energy to the inductive circuit element to generate an output voltage of the switching converter circuit, the output voltage having an alternating current (AC) signal component and a direct current (DC) signal component; a current sensing circuit configured to generate a current sense signal representative of inductor current of the inductive circuit element, wherein an output of the current sensing circuit is coupled to a bias circuit node; and a dynamic bias circuit configured to apply a dynamic bias voltage to the bias circuit node, wherein the dynamic bias voltage includes an AC component that tracks the AC signal component of the output voltage.

Abstract: Microelectromechanical systems (MEMS) capacitive strain gauge sensors are described. The strain gauge sensors include a lever configured to mechanically amplify a strain response. In some embodiments, an anchored beam is coupled to the effort arm of the lever and a movable sensing finger to the resistance arm. The effort arm may be shorter than the resistance arm, thus providing a mechanical amplification.

Abstract: One embodiment is a system for estimating an internal temperature of a battery including a first circuit for receiving a system input signal comprising a measurement of at least one observable quantity associated with the battery and outputting an average battery temperature signal based on the system input signal; and an estimator for receiving the system input signal and the average battery temperature signal and estimating an internal temperature of the battery based on the received signals, wherein the estimator comprises a lumped thermal model of the battery comprising a plurality of parameters.

Abstract: The present disclosure describes a system for detecting abnormal blood pressure or blood volume in a user, the system comprising a processing system; a pulse transit time (PTT) detection system for providing a PTT signal indicative of a PTT of the user to the processing system, wherein PTT of the user is used as a surrogate for a blood pressure (BP) of the user; and an electrodermal activity (EDA) detection system for providing an EDA signal indicative of an EDA of the user to the processing system; wherein the processing system processes the PTT signal and the EDA signal to determine an index indicative of an abnormal blood pressure or blood volume of the user.

Abstract: One embodiment is a method for estimating an internal temperature of a battery, the method comprising obtaining multiple terminal impedance measurements for the battery, wherein each of the terminal impedance measurements is obtained at a different one of a plurality of frequencies; automatically selecting one of a plurality of battery models using on a value of a parameter of the battery, wherein each of the battery models has been trained and corresponds to a different range of values for the battery parameter and wherein the value of the parameter of the battery falls within the range of values for the battery parameter corresponding to the selected one of the plurality of battery models; and applying the selected one of the plurality of battery models to the multiple terminal impedance measurements to estimate the internal temperature of the battery.

Abstract: Systems and methods of implementing a more efficient and less resource-intensive CNN are disclosed herein. In particular, applications of CNN in the analog domain using Sampled Analog Technology (SAT) methods are disclosed. Using a CNN design with SAT results in lower power usage and faster operation as compared to a CNN design with digital logic and memory. The lower power usage of a CNN design with SAT can allow for sensor devices that also detect features at very low power for isolated operation.

Abstract: According to various aspects, systems and methods are provided for secure communication between a passive sensor node and a reader. A passive sensor node may be used for monitoring in a variety of situations. A reader may power the passive sensor while communicating with the passive sensor. In some scenarios, it may be necessary or desirable to provide security between the passive sensor and the reader. According to one aspect, the reader may send a first message initiating communication with the passive sensor, which may respond with a second message including encrypted data. An authorized reader may decrypt the data and respond with data encrypted based on the second message in a third message, which may be used by the device to authenticate the reader.

Abstract: Electrical overstress protection for high speed applications is provided. In certain embodiments, a method of distributed and customizable electrical overstress protection for a semiconductor die is provided. The method includes configuring a heterogeneous overstress protection array that includes a customizable forward protection circuit electrically connected between a power high pad, a power low pad, and a signal pad and distributed across the semiconductor die, including selecting a number of segmented overstress protection devices from a plurality of available overstress protection devices of the customizable protection circuit.

Abstract: System and apparatus for pulse oximetry. Systems, methods, and devices are presented for placement of the hardware on a body part where detracting signals are strong. In one example, detracting signals include signals from respiration. In various examples, the body part the oximeter is placed on is a wrist, chest, or arm. A computationally efficient pipeline is presented that allows for reliable and robust SpO2 estimation.

Abstract: A deskew system can be used to adjust signal characteristics such as pulse width and edge timing. In an example, a deskew system can include multiple timing control cells and each cell can operate in one of multiple different modes according to respective mode control signals. The modes can include at least a signal delay mode and a signal pulse width adjustment mode. In an example, a first cell in a deskew system can be configured to receive a test input signal at a first input node and, in response, provide a deskew output signal at a first output node. The deskew output signal can be based on the test input signal, a pulse width adjustment provided by the first cell, and on a delayed signal, corresponding to the input signal, that is provided by a subsequent cell in the series.

Abstract: A device for proximity detection includes multiple electrodes and an impedance sensor coupled to the electrodes. The impedance sensor may include three impedance elements and a sensing element arranged in a bridge configuration to offset an external impedance and detect changes to impedance in the environment of the device. The device further includes a proximity detector that obtains sensor measurements between multiple subsets of electrodes and analyzes the sensor measurements to determine whether an object is approaching the device.

Abstract: A method and electronic device for configuring a PUF, wherein: PUF cells are configured to use a signal path; determining a winner of racing pairs of PUF cells in a first round and in a second round wherein winners of the first round are raced; the first and second round are repeated for different signal paths; determining, for each signal path, a comparison metric, wherein the comparison metric is based on the count of the outputs of the PUF cells having the signal path in common; determining an optimum signal path for the PUF from the respective comparison metrics; and configuring the PUF to use the optimum signal path.

Abstract: Apparatus and methods for phasing detection of asynchronous dividers are provided herein. In certain embodiments, a clock and data recovery system includes a first divider that outputs a first divided clock signal, a second divider that outputs a second divided clock signal, and an asynchronous clock phasing detection circuit that generates a detection signal indicating a relative phase difference between the first divided clock signal and the second divided clock signal. The asynchronous clock phasing detection circuit includes a quantization and logic circuit that generates an output signal indicating when the first divided clock signal and the second divided clock signal are in different states, an oscillator that outputs a control clock signal, a first counter controlled by the control clock signal and configured to count the output signal, and a control circuit that processes a first count signal from the first counter to generate the detection signal.

Abstract: Apparatus and methods for controlling a clock signal are provided. In certain embodiments, a semiconductor die includes a core circuit and a clock interface circuit that provides a clock signal to the core circuit. The clock interface circuit includes an oscillator for generating an oscillator signal, and a comparator for controlling operation of the clock interface circuit in a selected clock control mode based on comparing an electrical characteristic of the clock interface pin to a comparison threshold. The selected clock control mode is chosen from a first clock control mode in which the clock interface circuit generates the clock signal based on an input clock signal received on a clock interface pin, or a second clock control mode in which the clock interface circuit generates the clock signal based on the oscillator signal.