Abstract

Aggressive scaling down of transistor dimensions has made process-aware circuit modeling a crucial task. Achieving accurate circuit modeling requires lengthy and resource intensive simulations. Machine Learning-based surrogate models, offering computational efficiency and speed, are viable alternatives to traditional simulators. This paper introduces a meta-learning approach designed to accurately capture process induced variations in the leakage power of VLSI circuits. The impact of a wide range of fluctuations in operating conditions, including temperature (-55°C to 125°C) and supply voltage (±10%) has also been incorporated for leakage modeling. The proposed meta-learning model is versatile, enhancing the performance of underlying baseline machine learning models while eliminating the need for time-consuming hyperparameter optimization. Our experiments on leakage estimation using 16 and 7 nanometer FinFET technology nodes demonstrate an average improvement of up to 50% and 48% in Mean Absolute Percentage Error compared to stand-alone baseline models.

Abstract

Biomolecules play indispensable roles in all life processes, including disease development, so their accurate detection is critical to cell investigation, medical diagnosis, and treatment. Radio Frequency (RF) sensing has become a popular testing technique compared to traditional methods for biomolecule analysis, providing results in less time using less volume of samples. It allows rapid, sensitive, real-time measurements and label-free techniques. However, for taking the signals from biomolecules over the RF-based sensors we need to connect them with the Vector Network Analyzer (VNA) which is a bulky and costly device. To develop an RF sensing based a true lab-on-chip (LoC) device, the paper presents a fully integrated low-power less-area on-chip single port CMOS VNA designed in 65nm CMOS technology to detect the bio-molecule The proposed design works in a tunable frequency range of 0.5 GHz to 2.5 GHz, ensuring much higher precision. Using an RLC equivalent of an Interdigitated capacitor (IDC) sensor, a fully integrated architecture for detecting $S_{11}$ of the biomolecules has been introduced. A resistive bridge coupler is used for wideband operation with a directivity of 14.89dB up to 2.5 GHz. Also, a high-linearity LNA (low noise amplifier) is designed with a linearity of -13dB and a gain of 14dB. The LNA has a low NF of 3.21dB. The design occupies an active area of 0.01767mm^2 and consumes power of 41mW from a 1 V supply.

Abstract

An on-chip resistance amplifier which amplifies the resistance of a small on-chip resistor in die size is provided. The amplifier is a two-terminal circuit of which a high voltage terminal ranging from 0.4 Volts to 3.6 Volts and a second low voltage terminal at the ground includes a small on-chip resistor, a Voltage divider, an operational amplifier op-amp, a NMOS transistor. The voltage divider works in ultra-low power. The voltage (V) at high voltage terminal is divided by some gain A which is V/A, a second voltage. The second voltage is given to the on-chip resistor R. The current generated by on-chip resistor is passed through the higher voltage terminal and the resistance seen at the higher terminal is the amplified resistance of A*R.

Abstract

A constant reference voltage/current generating circuit connected between a power supply voltage source and a ground that provides a constant reference voltage/current at an output terminal. The constant reference voltage/current generating circuit includes one or more transistors that generates the constant reference voltage by determining a difference between a gate-source voltage of a first transistor and a gate source voltage of a second transistor with respect to a temperature. The constant reference voltage is mirrored at the output terminal of the constant reference voltage/current generating circuit using a current mirror circuit. The current mirror circuit is connected to the constant reference voltage/current generating circuit.

Abstract

No Results Found

Abstract

In this paper, a cost-effective and easy-to- implement auto-trim technique is introduced for PTAT or CTAT resistance based current references. The resistance with a process-insensitive temperature coefficient requires only a single point trim at room temperature, achieving process and temperature-insensitive current. The approach utilizes a data comparison method where on-chip current data is compared with off-chip reference data to trim the resistance of the current reference. The off-chip reference data is generated using a low-cost external resistor that is used only during the trimming operation. The proposed trimming sensor effectively calibrates the current, offering precision close to manual trimming, leading to cost, time, and resource savings. To validate the working of the proposed technique, the auto trim sensor with on-chip current reference is designed in TSMC 180nm technology. The auto trim sensor calibrates the on-chip current from ±25% (due to voltage and resistance process variation) to ±1.5% across the process and 3σ mismatch

Abstract

Various studies have shown the advantages of using Machine Learning (ML) techniques for analog and digital IC design automation and optimization. Data scarcity is still an issue for electronic designs, while training highly accurate ML models. This work proposes generating and evaluating artificial data using generative adversarial networks (GANs) for circuit data to aid and improve the accuracy of ML models trained with a small training data set. The training data is obtained by various simulations in the Cadence Virtuoso, HSPICE, and Microcap design environment with TSMC 180 nm and 22 nm CMOS technology nodes. The artificial data is generated and tested for an appropriate set of analog circuits and digital cells. The experimental results show that the proposed artificial data generation significantly improves ML models and reduces the percentage error by more than 50% of the original percentage error, which were previously trained with insufficient data. Furthermore, this research aims to contribute to the extensive application of AI/ML in the field of VLSI design and technology by relieving the training data availability-related challenges.

Abstract

The paper presents a 0.5 V, ultra-low power current, and voltage reference circuit in a single block, giving reference values of 90.7 pA and 288 mV. The proposed block uses proper addition of CTAT and PTAT curves, resulting in an excellent temperature coefficient of 15.2 ppm/°C and 36.8 ppm/°C for compensated current and voltage values, respectively, at a nominal supply of 0.5 V for a wide temperature range of −55 °C to 100 °C. Usage of gate leakage transistors in place of resistors helps in reducing the power and area of the circuit to 0.087 mm2. The circuit is implemented in 90 nm technology and operates effectively across a wide voltage range of 0.5 V–2.6 V with a supply sensitivity of 0.028 %/V and 0.154 %/V for current and voltage reference, respectively. The entire circuit takes a power of 275.26 pW at nominal conditions.

Abstract

Univariate regression trees have representation problems for non-orthogonal regression functions. Ensembles of univariate regression trees have better representational power. In some cases, weighted ensembles have shown better performance than unweighted ensembles. In this paper, we study the properties of ensembles of regression trees by using regression classification models. We propose a theoretical framework to study the representational power of infinite-sized weighted ensembles, consisting of randomised finite-sized regression trees. We show for some datasets that the weighted ensembles may have better representational power than unweighted ensembles, but the performance is highly dependent on the weighting scheme and the properties of datasets. Our model cannot be used for all the datasets. However, for some datasets, we can accurately predict the experimental results of ensembles of regression trees.

Abstract

Skip to content IOP Science home Accessibility Help Search Journals Books Publishing Support Login Engineering Research Express Inclusive Publishing Trusted Science, find out more. Purpose-led Publishing, find out more. ACCEPTED MANUSCRIPT A label-free sensing of creatinine using radio frequency-driven lab-on-chip (loc) system Andleeb Zahra1, Swarnim Sinha2, Alimpan Modak3, Imran Siddiqui4, Azeemuddin Syed5, Prabhakar Bhimalapuram6, Tapan K. Sau7, Pawan Kumar8 and Zia Abbas9 Accepted Manuscript online 2 August 2024 • © 2024 IOP Publishing Ltd What is an Accepted Manuscript? DOI 10.1088/2631-8695/ad6ad5 DownloadAccepted Manuscript PDF Download PDF Article metrics 6 Total downloads Submit Submit to this Journal Permissions Get permission to re-use this article Share this article Article and author information Abstract This paper presents a promising avenue of Radio Frequency (RF) biosensors for sensitive and real-time monitoring of creatinine detection. Knowing creatinine levels in the human body is related to its possible association with renal, muscular, and thyroid dysfunction. The detection was performed using an Inter-Digitated Capacitor (IDC) made of copper (Cu) metal over an FR4 substrate. To demonstrate our methodology, we have chosen Phosphate Buffer (PB) as our solvent for making the creatinine solutions of different concentrations. Moreover, Assayed Chemistry Control (ACC), a reference control consisting of human serum-based solutions has been mixed with the different concentrations of creatinine in a ratio of 1:9 to spike the creatinine value in the ACC solution. The sensor has been designed using a High-Frequency Structure Simulator (HFSS) tool with an operating frequency of 2.53 GHz. Then the design is fabricated over the FR4 printed circuit board (PCB) and tested using a Vector Network Analyzer (VNA). However, the sensitive area of the IDC is introduced to grade 4 Whatman filter paper for the Sample Under Test (SUT) handling unit. The main advantage of using Whatman filter paper is that the uniform spreading of liquid reduces experimental error, and less volume is required for testing the sample. The principal idea implemented in the biosensor design is to track the shift in the operating frequency in the presence of different concentrations of creatinine mix in ACC solution with Phosphate Buffer (PB) solution as a reference.