Showing papers by "Alessandro Trifiletti published in 2019"

Area-Efficient Low-Power Bandpass Gm-C Filter for Epileptic Seizure Detection in 130nm CMOS

Abstract: A low-power 6th-order Butterworth bandpass filter has been designed for the front-end of an integrated neural recording system. The passband has been set to 250-500Hz to allow recording the fast ripple (FR) associated with epileptic seizure onset and filter out all other undesired components of the neural signals. The filter is composed of 3 Gm-C biquad stages. Low-power operation is achieved by biasing the MOS devices in the sub-threshold region, and using a dual power supply of ±0.5V. The filter achieves a power consumption of $3.8\ \boldsymbol{\mu}\mathbf{W}$ with a load of 1pF, a bandwidth of 243Hz, and the estimated size of the layout is only 0.1mm2.

Wideband Spectrum Estimation in Frequency Dense Environments

Abstract: The majority of new radar applications requires to analyse a large frequency spectrum in real time, in order to perform effective detection and recognition in frequency dense environments. When the spectrum is very large, the samples representing a wideband signal must be collected at a much lower rate than the Nyquist rate corresponding to the highest frequency of the spectrum. We focus our attention on the two most promising methodologies proposed to perform this task. The first one is based on the correlation of different sub-Nyquist asynchronous channels. The second method is based on a preliminary analog processing of the wideband signal, followed by digital sub-Nyquist sampling. Both methods reach fair performances when the spectrum density is not too high and/or the input signal to noise ratio is sufficiently high. This paper combines the two methods, in order to work efficiently also when the previous conditions are not satisfied.

A low-power class-AB Gm-C biquad stage in CMOS 40nm technology

Abstract: A low-power class-AB Gm-C biquad stage has been designed using a voltage buffer based on error amplifiers and a push-pull current mirror. The class-AB architecture allows good power efficiency by lowering the required bias current. The biquad stage consumes $250\boldsymbol{\mu} \mathbf{A}$ from a 1.2V supply, and achieves a resonance frequency of 2.2MHz with a Q of 2. The SFDR (spurious-free dynamic range) with a two-tone test is 48dB and the SNR (signal-to-noise ratio) is 44.4dB, with a 400mVpp differential input signal. A pseudo-differential architecture allows large bandwidth and lower power consumption in the transconductance stages. The stage can be used to synthetize lowpass and bandpass filters composed of low-Q stages.