A New Technique for Designing High-Speed Frequency Counters

Some basic difficulties in the implementation of high-speed frequency counters are discussed. A new method which avoids most of these difficulties is described. The method essentially consists of binary prescaling the input frequency to a value easily manageable with decade counters and subsequently multiplying the resultant count in the decade counters by the prescaling factor. A simple digit serial multiplier for this purpose is iliustrated along with the system design of a 150-MHz frequency counter. Finally, the advantages of the new approach are discussed.