106 research outputs found
breaking the boundaries between analogue and digital
No full textSubject Editor Paolo Crovetti spotlight on future information processin
Spectral characteristics of DDPM streams and their application to all‐digital amplitude modulation
No full textAbstract A new closed‐form expression of the spectral coefficients of the digital streams obtained by dyadic digital pulse modulation is presented and validated in this letter. The new expression provides in‐depth insight into the spectral properties of dyadic digital pulse modulation, revealing its applicability as an all‐digital bandpass amplitude modulation technique. Simulations and measurements on a proof‐of‐concept dyadic digital pulse modulation amplitude modulator prototype demonstrate the effectiveness of the approach
Interference of Spread-Spectrum Modulated Disturbances on Digital Communication Channels
No full textIn this paper, the effects of random spread spectrum (SS) electromagnetic interference (EMI) on digital communications are addressed. For this purpose, the influence of EMI on a communication channel is described in the framework of information theory in terms of an equivalent channel capacity loss, which is analytically predicted and validated by experimental results. The EMI-induced channel capacity loss for non-modulated and SS-modulated interference generated by a switching-mode DC-DC power converter are then evaluated for different EMI and channel characteristics so that to compare different scenarios of practical interest
The Digital-Based Operational Transconductance Amplifier: Evolution and Perspective
No full textThe evolution of the Digital-Based Operational Transconductance Amplifier (DB-OTA), which was initially introduced to address the challenges related to the implementation of analog functions in aggressively scaled technology nodes is reviewed in this paper, starting from the first proof-of-concept prototype up to the most recent ultra-compact area, ultra-low voltage and ultra-low power solutions. The improvement in performance and the potential of this approach in meeting the requirements of Internet of Things (IoT) sensor nodes and next-generation biosensing will be discussed
A Sub-Leakage pW-Power Hz-Range Relaxation Oscillator Operating with 0.3V-1.8V Unregulated Supply
No full textA pW-power versatile relaxation oscillator operating from sub-threshold (0.3V) to nominal voltage (1.8V) is presented, having Hz-range frequency under sub-pF capacitor. The wide voltage and low sensitivity of frequency/absorbed current to the supply allow the suppression of the voltage regulator, and direct powering from harvesters (e.g., solar cell, thermal from machines) or 1.2-1.5V batteries. A 180nm testchip exhibits a frequency of 4 Hz , 10%/V supply sensitivity at 0.3-1.8V, 8-18pA current, 4%/°C thermal drift from -20°C to 40°C
Design of Digital OTAs With Operation Down to 0.3 V and nW Power for Direct Harvesting
No full textIn this paper, passive-less fully-digital operational transconductance amplifiers (DIGOTA) for energy- and area-constrained systems are modeled and analyzed from a design viewpoint. The digital behavior of DIGOTAs is modeled as an equivalent small-signal differential-mode circuit with zero bias current, and a common-mode feedback loop operating as a self-oscillating threshold sampler. Such continuous-time equivalent circuits are used to derive an explicit model of the main performance parameters that are generally adopted to characterize OTAs. This provides an insight into circuit operation and allows to derive practical guidelines to achieve a given design target. Among the others, an explicit model is derived for the DC gain, the frequency response, the gain-bandwidth product, the input-referred noise, and the input offset voltage.
The models are validated via direct comparison with multi-die measurement results in CMOS 180 nm. From an application viewpoint, the voltage (power) reduction down to 0.25 V (subnW) uniquely enable direct harvesting (e.g., with solar cells), suppressing any intermediate DC-DC conversion stage. This further enhances the area efficiency advantage of DIGOTA stemming from its fully-digital nature, making it well suited for cost-sensitive and purely-harvested systems
Susceptibility to EMI of a Battery Management System IC for electric vehicles
No full textThe susceptibility to Electromagnetic Interference (EMI) of Battery Management Systems (BMSs) for Li-ion and LiPo battery packs employed in emerging electric and hybrid electric vehicles is investigated in this paper. To this purpose, a specif c test board is developed to experimentally assess the EMI susceptibility of a BMS front-end integrated circuit by direct power injection (DPI) and radiated susceptibility measurements. Experimental results are discussed highlighting different EMI-induced failure mechanisms observed during the tests
Investigation on the susceptibility of hall-effect current sensors to EMI
No full textIn this paper, the susceptibility to electromagnetic interference of Hall effect sensors is experimentally assessed. To this purpose, Bulk Current Injection and TEM cell Electromagnetic Interference immunity measurements are performed on a test board including a commercial Hall sensor for current monitoring. From such measurements, EMI-induced failures in the Hall effect sensor operation are highlighted. Moreover, the particular susceptibility of the Hall effect sensor to a tangential RF electric field excitation is highlighted by comparing the results of measurements carried out on the Hall sensor in different configurations. © 2011 EMC Europe
Standard Cell-Based Ultra-Compact DACs in 40nm CMOS
No full textIn this paper, very compact, standard cell-based Digital-to-Analog converters (DACs) based on the Dyadic Digital Pulse Modulation (DDPM) are presented. As fundamental contribution, an optimal sampling condition is analytically derived to enhance DDPM conversion with inherent suppression of spurious harmonics. Operation under such optimal condition is experimentally demonstrated to assure resolution up to 16 bits, with 9.4-239X area reduction compared to prior art. The digital nature of the circuits also allows extremely low design effort in the order of 10 man-hours, portability across CMOS generations, and operation at the lowest supply voltage reported to date. The limitations of DDPM converters, the benefits of the optimal sampling condition and digital calibration were explored through the optimized design and the experimental characterization of two DACs with moderate and high resolution. The first is a general-purpose DAC for baseband signals achieving 12-bit (11.6 ENOB) resolution at 110kS/s sample rate and consuming 50.8uW, the second is a DAC for DC calibration achieving 16-bit resolution with 3.1-LSB INL, 2.5-LSB DNL, 45uW power, at only 530um2 area
Fully-Digital Rail-to-Rail OTA with Sub-1,000 μm2 Area, 250-mV Minimum Supply and nW Power at 150-pF Load in 180nm
No full textA fully-digital operational transconductance amplifier (DIGOTA) architecture for tightly energy-constrained low-cost systems is presented. A 180nm DIGOTA testchip exhibits an area below the 1,000-μm2 wall, and 2.4-nW power under 150pF load, and a minimum supply voltage Vmin of 0.25 V. In the 0.3-0.5 V supply range, DIGOTA improves the areanormalized small (large) signal energy FoM by at least 836X (267X) over prior sub-500mV OTAs, while reducing area by 27-85X. The low-Vmin and nW-power features are shown to enable direct harvesting at the mm scale
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