Integrated circuit manufacturers provide libraries of pre-designed digital cells for digital circuit design. The transistor level implementation of the cells is not considered during the design procedure. The cells, such as buffers, logic gates, adders, flip-flops, etc. are used without modifications wherever needed. For that reason the cells are not fine tuned to their unique surrounding condi...

The field of optimisation is still not appropriately covered in modern computer programs for circuit analysis as SPICE. It was originally developed at the University of California at Berkeley. The last official release of SPICE 3f4 was published in 1992. It has numerous bugs, mainly memory leaks. In order to implement optimisation methods most bugs were tracked down and fixed. Several well-know...

In the paper four approaches of upgrading analog circuits analysis tools (SPICE was used) with optimisation loops are compared. In the first approach the optimisation algorithm is coded in Mathematica, which calls SPICE for every circuit analysis. In the second approach the algorithm is coded in Nutmeg. (Nutmeg is an interpreter designed as a user interface for SPICE, but it has all properties ...

Though rather awkward and limited in its usage, SPICE has been used by several authors solving their various optimisation problems. In this paper we propose how some generic optimisation algorithms can be integrated into SPICE. The implemented program has proven to be an extremely efficient optimisation tool for an experienced circuit designer. It is free of charge available at our web site (ht...

Pre-designed cells, such as buffers, adders and flip-flops are provided by foundries and used in digital circuit design. Actual cell implementation at transistor level is not considered during the synthesis of a digital circuit. The paper describes four cases of transistor-level cell optimisation that can be employed to reach arbitrary customisation. Due to the landscape of the cost functions a...

The field of optimisation is still not appropriately covered in modern computer programs for circuit analysis as SPICE, which was originally developed at the University of California at Berkeley. The last official release of SPICE was published in 1992 and includes interactive interpreter language called Nutmeg, which is at first glance very convenient for coding optimisation loops. But it turn...

Utilities account for a significant portion of the fixed cost associated with running a petrochemical plant, however, utility optimisation has not received much focus until recently. This change was driven by rising energy prices, stricter environmental policies, and the threat of climate change. Several utilities are used including steam, compressed air, nitrogen, cooling water, refrigeration ...