Chip-size and power consumption of ASICs and digital signal processors for low-power signal-processing

Signal-processing in battery-powered telecommunication equipment such as cordless telephone or radiotelephone can be done using a standard DSP (digital signal processor), a hardwired digital ASIC (application-specific integrated circuit) or an SC-circuit. Whether one of these alternatives is useful and advantageous for a particular application is determined by its cost and power consumption. A simple method for estimating the current consumption and chip surface is developed. It starts from an estimation of the required processing power. Characteristic figures for the current consumption and surface in relation to the processing power of the three alternatives are driven from a typical building block. Correcting factors are introduced to account for the process and for a more than usual amount of overhead circuitry. The digital hardwired and the SC alternatives both offer a specific power consumption which is by a factor of 10 lower than that with a DSP