Snezana Stojanovic

A 13.2b optical proximity sensor system with 130klx ambient light rejection capable of heart rate and blood oximetry monitoring

A system for measuring optical proximity based on reflection of modulated light is presented. Its novel input stage topology comprising an AC coupled TIA and a two stage DC rejection circuit based on a synthesized inductive impedance, provides readouts with a resolution better than 13.2 ENOB. This allows the sensor system to be used without modifications also for heart rate and blood oximetry monitoring.

9.5 A 1.8V true-differential 140dB SPL full-scale standard CMOS MEMS digital microphone exhibiting 67dB SNR

Over the last few years, robust MEMS microphones have gained significant market share in consumer applications such as mobile phones and hearing aids. The consumer market is demanding improved quality for audio recording, while also being capable of suppressing high-energy disturbers, e.g., wind noise. The challenge is to achieve both high DR and SNR at low supply voltages that limit signal swing. Signal levels are expressed in dB Sound-Pressure-Level (dB SPL) with respect to the human hearing threshold at a sound pressure of 20µPa corresponding to 0dB SPL. Todays mass-market MEMS digital microphone solutions typically process sound up to 120dB SPL [1,2].