A 12-bit Current-Steering Segmented DAC with Digital Foreground Calibration

This paper presents a Variable Gain Amplifier (VGA) designed in a 0.18 μm CMOS process to operate in an impedance sensing interface. Based on a transconductance-transimpedance (TC-TI) approach with intermediate analog-controlled current steering, it exhibits a gain ranging from 5 dB to 38 dB with a constant bandwidth around 318 kHz, a power consumption of 15.5 μW at a 1.8 V supply and an active area of 0.021 mm2.

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Static and dynamic nonlinearity compensation techniques for high performance current-steering digital-to-analog converters

10.31274/etd-180810-1364 ◽

2010 ◽

Author(s):

Tao Zeng

Keyword(s):

High Performance ◽

Current Steering ◽

Nonlinearity Compensation ◽

Digital To Analog Converters ◽

Digital To Analog ◽

Dynamic Nonlinearity

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Quantifying ionospheric effects on global 21-cm observations

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab429 ◽

2021 ◽

Vol 503 (1) ◽

pp. 344-353

Author(s):

Emma Shen ◽

Dominic Anstey ◽

Eloy de Lera Acedo ◽

Anastasia Fialkov ◽

Will Handley

Keyword(s):

Parameter Space ◽

Spatial Model ◽

Ionospheric Effects ◽

Temporal Variance ◽

Foreground Calibration ◽

Over Time

ABSTRACT We modelled the two major layer of Earth’s ionosphere, the F-layer and the D-layer, by a simplified spatial model with temporal variance to study the chromatic ionospheric effects on global 21-cm observations. From the analyses, we found that the magnitude of the ionospheric disruptions due to ionospheric refraction and absorption can be greater than the expected global 21-cm signal, and the variation of its magnitude can differ, depending on the ionospheric conditions. Within the parameter space adopted in the model, the shape of the global 21-cm signal is distorted after propagating through the ionosphere, while its amplitude is weakened. It is observed that the ionospheric effects do not cancel out over time, and thus should be accounted for in the foreground calibration at each timestep to account for the chromaticity introduced by the ionosphere.

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1.0 V-0.18 µm CMOS Tunable Low Pass Filters with 73 dB DR for On-Chip Sensing Acquisition Systems

Electronics ◽

10.3390/electronics10050563 ◽

2021 ◽

Vol 10 (5) ◽

pp. 563

Author(s):

Jorge Pérez-Bailón ◽

Belén Calvo ◽

Nicolás Medrano

Keyword(s):

Power Consumption ◽

Dynamic Range ◽

Low Voltage ◽

Cutoff Frequency ◽

Cmos Technology ◽

Active Area ◽

Current Steering ◽

Low Pass ◽

On Chip ◽

Low Pass Filters

This paper presents a new approach based on the use of a Current Steering (CS) technique for the design of fully integrated Gm–C Low Pass Filters (LPF) with sub-Hz to kHz tunable cut-off frequencies and an enhanced power-area-dynamic range trade-off. The proposed approach has been experimentally validated by two different first-order single-ended LPFs designed in a 0.18 µm CMOS technology powered by a 1.0 V single supply: a folded-OTA based LPF and a mirrored-OTA based LPF. The first one exhibits a constant power consumption of 180 nW at 100 nA bias current with an active area of 0.00135 mm2 and a tunable cutoff frequency that spans over 4 orders of magnitude (~100 mHz–152 Hz @ CL = 50 pF) preserving dynamic figures greater than 78 dB. The second one exhibits a power consumption of 1.75 µW at 500 nA with an active area of 0.0137 mm2 and a tunable cutoff frequency that spans over 5 orders of magnitude (~80 mHz–~1.2 kHz @ CL = 50 pF) preserving a dynamic range greater than 73 dB. Compared with previously reported filters, this proposal is a competitive solution while satisfying the low-voltage low-power on-chip constraints, becoming a preferable choice for general-purpose reconfigurable front-end sensor interfaces.

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