A system and method for fast converging gain calibration for phase lock loops (PLL) are herein disclosed. According to one embodiment, a method includes receiving, with a voltage generation circuit, an input value representing a difference between a sampled voltage and a reference voltage, and adjusting, with the voltage generation circuit, the reference voltage by generating a voltage output based on the difference represented by the input value.

A wireless communication device converts a signal component, which has one of distributed frequency bands in an analog RF signal and passes through one of a plurality of bandpass filters, into digital data with an AD converter that carries out undersampling. A sampling frequency of the AD converter is set so that frequencies which are integral multiples of a Nyquist frequency based on the sampling frequency do not fall within frequency bands of signal components which are of the RF signal and are to pass through the respective plurality of bandpass filters.

A position sensing system for a rotating object may include analog conditioning circuitry, analog to digital converter circuitry, and a controller. The analog conditioning circuitry may identify a half cycle of an analog input signal received from a sensor, which has a variable period and a variable magnitude. The analog to digital converter circuitry may process the input signal during the variable period. The controller may control the analog to digital converter circuitry to compare a magnitude of the identified half cycle of a first variable period of the input signal to a magnitude of the identified half cycle of a second variable period of the input signal. The controller may generate an output signal when a difference between the magnitude of the identified half cycle of the first variable period and the magnitude of the identified half cycle of the second variable period is greater than a predetermined threshold.

A high dynamic range sensing front-end for bio-signal recording systems in accordance with embodiments of the invention are disclosed. In one embodiment, a bio-signal amplifier includes an input signal, where the input signal is modulated to a predetermined chopping frequency, a first amplifier stage, a parallel-RC circuit connected to the first amplifier stage and configured to generate a parallel-RC circuit output by selectively blocking an offset current, a second amplifier stage connected to the parallel-RC circuit that includes a second input configured to receive the parallel-RC circuit output and generate a second output that is an amplified version of the input signal with ripple-rejection. Further, the bio-signal amplifier can also include an auxiliary path configured for boosting input impedance by pre-charging at least one input capacitor. In addition, the bio-signal amplifier can also include a DC-servo feedback loop that includes an integrator that utilizes a duty-cycled resistor.

A system and method for diagnosing load compressor health state for an auxiliary power unit that includes a power compressor, a combustor, a power turbine, and a load compressor is provided. The auxiliary power unit is operated and bleed air is discharged from the load compressor at a bleed air pressure. Using a pressure sensor, the bleed air pressure discharged from the load compressor is sensed and supplied to a processor. In the processor, power compressor health state is diagnosed based solely on the sensed bleed air pressure.

A radio frequency digital-to-analog converter (RFDAC) circuit includes an RFDAC array circuit including an array of cells arranged into a plurality of segments. Each segment of the plurality of segments is configured to process input data signals. The RFDAC array circuit is configured to process an input data based on activating a set of segments of the plurality of segments, forming a set of active segments, and when the sign of the input data is changed, deactivate a partially active segment of the set of active segments and activate a sign change segment within the RFDAC array circuit. The sign change segment includes a segment within the plurality of segments of the RFDAC array circuit that is different from the set of active segments.

Various examples are directed to systems and methods for providing correction to cascaded signal components. A correction signal may be applied to multiple signal components in a set of cascaded signal components.

According to one aspect of the invention, a method for making relatively high resolution measurements using relatively low resolution devices includes the steps of: deriving a first anticipated measurement value; using the first anticipated measurement value as an initial feed-forward signal; comparing the initial feed forward signal to a received signal from a sensor, thereby generating a compared signal; scaling the compared signal to full scale of an analog-to-digital converter, thereby generating a scaled signal; delivering the scaled signal in binary form for computation; and iteratively performing the comparing step until the compared signal is below a predetermined threshold value.

A circuit device includes an A/D conversion circuit that performs an A/D conversion of a temperature detection voltage, a digital filter that performs digital filter processing of A/D output temperature detection data, a selector that selects A/D output temperature detection data during an activation period and selects filter output temperature detection data during a normal operation period after the activation period, a digital signal processing circuit that outputs frequency control data of an oscillation frequency based on selector output temperature detection data, and an oscillation signal generation circuit that generates an oscillation signal of an oscillation frequency set by frequency control data.

A circuit device includes an A/D conversion circuit that performs an A/D conversion of a temperature detection voltage, a digital filter that performs digital filter processing of A/D output temperature detection data, a selector that selects A/D output temperature detection data during an activation period and selects filter output temperature detection data during a normal operation period after the activation period, a digital signal processing circuit that outputs frequency control data of an oscillation frequency based on selector output temperature detection data, and an oscillation signal generation circuit that generates an oscillation signal of an oscillation frequency set by frequency control data.