Digital-Based Analog Processing in Nanoscale CMOS ICs for IoT Applications

L'abstract è presente nell'allegato / the abstract is in the attachmen

Performance enhancement in the desing of amplifier and amplifier-less circuits in modern CMOS technologies.

In the context of nowadays CMOS technology downscaling and the increasing demand of high performance electronics by industry and consumers, analog design has become a major challenge. On the one hand, beyond others, amplifiers have traditionally been a key cell for many analog systems whose overall performance strongly depends on those of the amplifier. Consequently, still today, achieving high performance amplifiers is essential. On the other hand, due to the increasing difficulty in achieving high performance amplifiers in downscaled modern technologies, a different research line that replaces the amplifier by other more easily achievable cells appears: the so called amplifier-less techniques. This thesis explores and contributes to both philosophies. Specifically, a lowvoltage differential input pair is proposed, with which three multistage amplifiers in the state of art are designed, analysed and tested. Moreover, a structure for the implementation of differential switched capacitor circuits, specially suitable for comparator-based circuits, that features lower distortion and less noise than the classical differential structures is proposed, an, as a proof of concept, implemented in a ΔΣ modulator

Design and Implementation of a Low‐Power Wireless Respiration Monitoring Sensor

Wireless devices for monitoring of respiration activities can play a major role in advancing modern home-based health care applications. Existing methods for respiration monitoring require special algorithms and high precision filters to eliminate noise and other motion artifacts. These necessitate additional power consuming circuitry for further signal conditioning. This dissertation is particularly focused on a novel approach of respiration monitoring based on a PVDF-based pyroelectric transducer. Low-power, low-noise, and fully integrated charge amplifiers are designed to serve as the front-end amplifier of the sensor to efficiently convert the charge generated by the transducer into a proportional voltage signal. To transmit the respiration data wirelessly, a lowpower transmitter design is crucial. This energy constraint motivates the exploration of the design of a duty-cycled transmitter, where the radio is designed to be turned off most of the time and turned on only for a short duration of time. Due to its inherent duty-cycled nature, impulse radio ultra-wideband (IR-UWB) transmitter is an ideal candidate for the implementation of a duty-cycled radio. To achieve better energy efficiency and longer battery lifetime a low-power low-complexity OOK (on-off keying) based impulse radio ultra-wideband (IR-UWB) transmitter is designed and implemented using standard CMOS process. Initial simulation and test results exhibit a promising advancement towards the development of an energy-efficient wireless sensor for monitoring of respiration activities