Tutorial on Battery Simulation-Matching Power Source to Electronic System

FREE-DOWNLOAD M Kulkarni Proc. 14th research VLSI Design and Test , 2010
chips, the influence of power reduction on battery lifetime is important for portable devices.
an electrical circuit model to simulate the performance of a battery as it powers the operation of a digital circuit. For a hypothetical electronic system containing 70 million gates implemented in 45nm CMOS technology the problem of finding a suitable battery is analyzed. The proposed three part solution consists of (1) circuit simulation to determine critical path delay and average current as functions of supply voltage, (2) battery simulation to determine its efficiency and lifetime (time between recharges) at various current loads and to find suitable batteries for the electronic system, and (3) derivation of operational modes (supply voltages and clock frequencies) for maximum performance and minimum energy, respectively. Most of the work on low power design is focused on designing circuits which consume lower energy and power. As far as the portable electronic devices are concerned, the ultimate aim is to achieve more battery lifetime or, for rechargeable source, perform most operations between consecutive recharges. Optimization of the circuit alone for power and energy may not always result in equivalent optimization of battery lifetime. So a study of the system consisting of battery and the circuit under consideration is required in order to achieve maximum battery lifetime. In general, this lifetime should be measured in terms of the duration of the system operation. A relevant measure is the number of useful clock cycles obtained per battery life or per battery recharge.