A 200 μA Duty-Cycled PLL for Wireless Sensor Nodes in 65 nm CMOS

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Design of a fully integrated CMOS highly temperature stable frequency reference

A new fully integrated frequency reference has been designed, fabricated and measured. The goal of the design procedure has been high stability of the frequency over temperature variations. This should be achieved using a CMOS technology without MEMS and crystals, while being restricted by a very low power budget. The frequency is designed based...

A Fully Integrated Bluetooth Low-Energy Transmitter in 28 nm CMOS With 36% System Efficiency at 3 dBm

We propose a new transmitter architecture for ultra-low power radios in which the most energy-hungry RF circuits operate at a supply just above a threshold voltage of CMOS transistors. An all-digital PLL employs a digitally controlled oscillator with switching current sources to reduce supply voltage and power without sacrificing its startup...

A 2.5-μW Beyond-the-Rails Current Sensor With a Tunable Voltage Reference and ±0.6% Gain Error From −40 ◦C to +85 ◦C

This letter presents a low-power, fully integrated current sensor for Coulomb-counting. It employs a hybrid delta–sigma modulator ( ΔΣM ) with an FIR-DAC to digitize the voltage drop across a shunt. The modulator’s first stage consists of a capacitively coupled chopper amplifier, which enables a beyond-the-rails (−0.3 to 5 V) input common...

A Highly Efficient Fully Integrated Active Rectifier for Ultrasonic Wireless Power Transfer

Ultrasonic wireless power transfer (WPT) has been proved to be a promising approach to power biomedical implants. To extract the energy generated from the transducer, a rectifier is typically required. Previous inductor-based rectifiers (SSHI and SECE) require a large off-chip inductor to achieve good performance, which is not desired for...

A Dynamically Reconfigurable Recursive Switched-Capacitor DC-DC Converter with Adaptive Load Ability Enhancement

Multiple voltage conversion ratio (VCR) recursive switched-capacitor (SC) DC-DC<br/>converters, based on a number of basic 2:1 converters, are widely used for on-chip power supplies due to their flexible VCRs for higher energy efficiency. However, conventional multi-VCR SC converters usually have one or more 2:1 converters unused for some VCRs,...

A Dynamically Reconfigurable Recursive Switched-Capacitor DC-DC Converter with Adaptive Load Ability Enhancement

Multiple voltage conversion ratio (VCR) recursive switched-capacitor (SC) dc-dc converters, based on several basic 2:1 converters, are widely used for on-chip power supplies due to their flexible VCRs for higher energy efficiency. However, conventional multiple VCR SC converters usually have one or more 2:1 converters unused for some VCRs,...