Hybrid design of an application-specific integrated chip for frequency-to-digital conversion

Abstract

Though the frequency measurement technique is well established, converting frequency to a digital world for real time systems is not an easy task. The task is further complicated by the absence of any standard peripheral integrated circuit chip for this application. The existing techniques of frequency measurement like direct frequency measurement and period measurement are not accurate at low and high frequencies respectively. This talk will elaborate the effort involved to realize a successful Frequency to Digital Converter (FDC) as an Application Specific Integrated Circuit (ASIC). The chip adopts an innovative frequency measurement technique called the hybrid technique. The hybrid technique has the advantage of both the direct frequency and period measurement techniques and is found to be very accurate at both low and high frequencies. The chip was designed and fabricated with stringent specifications to meet military applications. Extensive software simulations were done to ensure the proper functioning of the chip. The chip was then tested extensively over all frequencies and was found to operate successfully meeting all the specifications.