Sambhu Nath Pradhan

Work place: Department of ECE, National Institute of Technology Agartala, Agartala, 799046, India



Research Interests: Interaction Design, Computer systems and computational processes, Computer Architecture and Organization, Speech Synthesis, Algorithm Design


Sambhu Nath Pradhan is an assistant professor in the Department of ECE, National Institute of Technology Agartala. He received Ph.D. from Indian Institute of Technology Kharagpur and M.E. from Bengal Engineering and Science University in 2010 and 2004 respectively. His research interest includes low power design and testing and thermal aware logic synthesis.

Author Articles
Area-Power-Temperature Aware AND-XOR Network Synthesis Based on Shared Mixed Polarity Reed-Muller Expansion

By Apangshu Das Sambhu Nath Pradhan

DOI:, Pub. Date: 8 Dec. 2018

Modern Integrated circuits (ICs) suffer from excessive power and temperature issues because of embedding a large number of applications on small silicon real estate. Low power technique is introduced to reduce the power. With the reduction of power, area of circuit increases and vice versa. It shows a trade-off nature between them. Increase of area is against the trend of technology scaling which demands small area. Due to small area and high power dissipation, power-density increases. As power-density is directly converging into temperature, it emerges as a challenge in front of the VLSI design engineer to minimize the effect of temperature by reducing power-density. In this work, an attempt has been made to reduce the effect of power-density along with area and power so that AND-XOR based circuit is balanced in terms of area, power, and temperature. AND-XOR based reed-muller (RM) mixed polarity circuit forms are considered in this work. Polarity conversions are made in such a way that possibility of maximum sharing among the sub-function is increased. Genetic algorithm is (a non-exhaustive heuristic algorithm) used to select the polarity of the input variable for maximum sharing. The proposed synthesis approach shows 27.11%, 20.69%, and 32.30% savings in area, power, and power-density respectively than that of reported results. For the validation of the proposed approach, the best solutions are implemented in Cadence digital domain to obtain actual silicon area and power consumption. HotSpot tool is used to get the absolute temperature of the circuit.

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A CLB Priority based Power Gating Technique in Field Programmable Gate Arrays

By Abhishek Nag Sambhu Nath Pradhan

DOI:, Pub. Date: 8 May 2018

In this work, an autonomous technique of power gating is introduced at coarse level in Field Programmable Gate Array (FPGA) architecture to minimize leakage power. One of the major disadvantages of FPGA is the unnecessary power dissipation associated with the unused logic/inactive blocks. These inactive blocks in a FPGA are automatically cut-off from the power supply in this approach, based on a CLB priority algorithm. Our method focuses on introducing gating into both the logic blocks and routing resources of an FPGA at the same time, contrary to previous approaches. The proposed technique divides the FPGA fabric into clusters of CLBs and associated routing resources and introduces power gating separately for each cluster during runtime. The FPGA prototype has been developed in Cadence virtuoso spectrum at 45 nm technology and the layout of the proposed power gated FPGA is developed also. Simulation has been carried out for a ‘4 CLB’ prototype and results in a maximum of 55 % power reduction. The area overhead is 1.85 % for the ‘4 CLB’ FPGA prototype and tends to reduce with the increase in number of CLBs. The area overhead of a ‘128 CLB’ FPGA prototype is only 0.058 %, considering 4 sleep transistors. As an extension to the proposed gating in ‘4 CLB’ prototype, two techniques for an ‘8 CLB’ prototype are also evaluated in this paper, each having its own advantages. Due to the wake up time associated with power gated blocks, delay tends to increase. The wake-up time however, reduces with the increase in sleep transistor width.

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