A 200-μW Interface for High-Resolution Eddy-Current Displacement Sensors

This article presents a low-power eddy-current sensor interface for touch applications. It is based on a bang-bang digital phase-locked loop (DPLL) that converts the displacement of a metal target into digital information. The PLL consists of a digitally controlled oscillator (DCO) built around a sensing coil and a capacitive DAC, a...

A 200μW Eddy Current Displacement Sensor with 6.7nm_RMS Resolution

This paper describes a low-power eddy current displacement sensor intended for safety-critical touch applications. A sensing inductor is incorporated into a digital PLL to efficiently digitize the displacement of a flexible metal foil. At a stand-off distance of 500μm, the sensor achieves 6.7nm resolution in a 3kHz bandwidth over a 43μm range...

An Ultra-Low Phase Noise Class-F 2 CMOS Oscillator With 191 dBc/Hz FoM and Long-Term Reliability

In this paper, we propose a new class of operation of an RF oscillator that minimizes its phase noise. The main idea is to enforce a clipped voltage waveform around the LC tank by increasing the second-harmonic of fundamental oscillation voltage through an additional impedance peak, thus giving rise to a class-F 2 operation. As a result, the...

A Class-F CMOS Oscillator

An oscillator topology demonstrating an improved phase noise performance is proposed in this paper. It exploits the time-variant phase noise model with insights into the phase noise conversion mechanisms. The proposed oscillator is based on enforcing a pseudo-square voltage waveform around the LC tank by increasing the third-harmonic of the...