A Sub-1-V, 350-uW, 6.5-dB Integrated NF Low-IF Receiver Front-End for IoT in 28-nm CMOS

This letter presents a highly efficient low-intermediate frequency receiver front-end for Internet-of-Things applications. The lownoise trans-impedance amplifier (LNTA) combines a transformer-based network for scaling up the source impedance together with passive gmboosting and current-reuse techniques to achieve better noise and 12× current saving compared with a common-gate (CG) stage. A complex channel-selection filter with center frequency and passband of 2 and 1.4 MHz, respectively, is implemented after the passive mixer with a gmboosted CG stage. Built in 28-nm CMOS, the proposed receiver occupies an active area of 0.1 mm 2 , it is supplied with 0.9 V and consumes only 350 μW, while showing a minimum NF of 6.2 dB at the channel of interest. The RF performance of the proposed receiver is very competitive with the state-of-the-art ultralow-power receivers, while it consumes the lowest power

A 195.6dBc/Hz peak FoM P-N class-B oscillator with transformer-based tail filtering

A complementary p-n class-B oscillator with two magnetically coupled second harmonic tail resonators is presented. For the same oscillation amplitude (constrained by reliability considerations) and the same tank, the p-n oscillator achieves 3-4dB better Figure of Merit (FoM) than an n-only reference one. After frequency division by 2, the p-n oscillator has a measured phase noise that ranges from -150.8 to -151.5 dBc/Hz at 10MHz offset from the carrier when the frequency of oscillation is varied from 3.64 to 4.15GHz. With a power consumption of 6.3mW, a peak FoM of 195.6 dBc/Hz is achieved.This work was supported by the European Marie Curie Grant Agreement No 251399. Paulo Mendes research was partially supported by grant SFRH/BSAB/1245/2012.info:eu-repo/semantics/publishedVersio

Analysis and design of a 195.6 dBc/Hz peak FoM P-N class-B oscillator with transformer-based tail filtering

A complementary p-n class-B oscillator with two magnetically coupled second harmonic tail resonators is presented and compared to an N-only reference one. An in depth analysis of phase noise, based on direct derivation of the Impulse Sensitivity Function (ISF), provides design insights on the optimization of the tail resonators. In principle the complementary p-n oscillator has the same optimum Figure of Merit (FoM) of the N-only at half the voltage swing. At a supply voltage of 1.5 V, the maximum allowed oscillation amplitude of the N-only is constrained, by reliability considerations, to be smaller than the value that corresponds to the optimum FoM even when 1.8 V thick oxide transistors are used. For an oscillation amplitude that ensures reliable operation and the same tank, the p-n oscillator achieves a FoM 2 to 3 dB better than the N, only depending on the safety margin taken in the design. After frequency division by 2, the p-n oscillator has a measured phase noise that ranges from -150.8 to -151.5 dBc/Hz at 10 MHz offset from the carrier when the frequency of oscillation is varied from 7.35 to 8.4 GHz. With a power consumption of 6.3 mW, a peak FoM of 195.6 dBc/Hz is achieved.This work was supported by the European Marie Curie IAPP Grant Agreement N 251399.info:eu-repo/semantics/publishedVersio

Italian Association of Clinical Endocrinologists (AME) and Italian Chapter of the American Association of Clinical Endocrinologists (AACE) Position Statement : clinical Management of Vitamin D Deficiency in Adults

Vitamin D deficiency is very common and prescriptions of both assay and supplementation are increasing more and more. Health expenditure is exponentially increasing, thus it is timely and appropriate to establish rules. The Italian Association of Clinical Endocrinologists appointed a task force to review literature about vitamin D deficiency in adults. Four topics were identified as worthy for the practicing clinicians. For each topic recommendations based on scientific evidence and clinical practice were issued according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) System. (1) What cut-off defines vitamin D deficiency: even though 20 ng/mL (50 nmol/L) can be considered appropriate in the general population, we recommend to maintain levels above 30 ng/mL (75 nmol/L) in categories at risk. (2) Whom, when, and how to perform screening for vitamin D deficiency: categories at risk (patients with bone, liver, kidney diseases, obesity, malabsorption, during pregnancy and lactation, some elderly) but not healthy people should be screened by the 25-hydroxy-vitamin D assay. (3) Whom and how to treat vitamin D deficiency: beyond healthy lifestyle (mostly sun exposure), we recommend oral vitamin D (vitamin D2 or vitamin D3) supplementation in patients treated with bone active drugs and in those with demonstrated deficiency. Dosages, molecules and modalities of administration can be profitably individually tailored. (4) How to monitor the efficacy of treatment with vitamin D: no routine monitoring is suggested during vitamin D treatment due to its large therapeutic index. In particular conditions, 25-hydroxy-vitamin D can be assayed after at least a 6-month treatment. We are confident that this document will help practicing clinicians in their daily clinical practice

1.5-V high-performance SC filters in BiCMOS technology

The authors describe two low-voltage switched-capacitor (SC) filters: one can operate from a minimum supply of 1.5 V and the other from a minimum supply of 2 V (for typical parameter values). Both filters use a fully differential architecture and are fabricated in a standard BiCMOS technology. The lowest supply filter, operated from a 2-V supply, has an SNR (signal-to-noise ratio) of 92 dB and a THD (total harmonic distortion) of -70 dB for a 2.4-Vpp differential signal. Power consumption and area per pole are 60 μW and 0.18 mm2, respectively, with a clock frequency of 447 kHz. The realized filters can be used as building blocks to implement more complex functions, like the active synthesis of a given impedance in line-fed telecom system

An intuitive analysis of phase noise fundamental limits in LC oscillators

none2noAn intuitive yet sufficiently accurate analysis of the phase noise performance of various commonly used oscillator topologies, including most types of class-B (standard and with tail filter), class-C, transformer-based and class-F is used to compare their fundamental limitation. The excess noise factor, that represents the difference between the maximum achievable Figure of Merit (for a given quality factor) and the actual one is evaluated for several state-of the-art implementations.restrictedManstretta, Danilo; Castello, RinaldoManstretta, Danilo; Castello, Rinald

Low-voltage fully-differential switched-opamp bandpass ΣΔ modulator

The paper deals with the design of a low-voltage bandpass ΣΔ modulator implemented with the switched-capacitor technique. To use standard technology (no low-threshold devices) and without an on-chip voltage multiplier, the switched-opamp technique has been adopted. The basic building blocks for the construction of a ΣΔ modulator (SC integrator, quantiser, and feedback DAC) are proposed in a fully differential version. In addition, they have been improved with respect to those previously reported to give a larger output swing at a higher sampling frequency and without any voltage reference. The validity of the proposed circuits is demonstrated by the realisation of a second-order bandpass ΣΔ modulator operating with a single 1 V supply within a standard 0.5 μm CMOS technology (VTHn=0.65 V, VTHp=0.7 V). The modulator operates at a sampling frequency of 1.8 MHz with a full-scale input range of 2 Vpk-pk and achieves a 45 dB dynamic range in a 20 kHz bandwidt

Finite gain compensated double-sampled switched-capacitor integrators for high-Q bandpass filters

A technique for the compensation of the operational amplifier (op-amp) finite gain error in the switched-capacitor (SC) integrator is proposed. Two possible SC integrators implementing the proposed technique are given. Both implementations allow the use of the double-sampling technique to increase by a factor of two the maximum speed of operation. The compensation operation consists in memorizing a sequence of output values of the SC integrator, and using them in the proper clock period to compensate the error due to the nonideal virtual ground. The compensation is mostly effective in a narrow frequency range centered around one specific frequency. The circuits implementing this technique are therefore particularly useful for high-Q high-frequency bandpass filters. The case of a biquadratic bandpass filter is reported as an exampl