TIME INTERVAL TO DIGITAL CONVERTER WITH SMOOTHING

摘要

An up/down tracking counter stores a digital count signal equal to the time interval to be converted and provides this signal as the parallel digital output of the converter. Prior to the interval to be converted the count from the up/down counter is loaded into a down counter. At the leading edge of the interval to be converted the down counter is counted down, from the count loaded therein, by a clock signal until the occurrence of the trailing edge of the interval. A decision PROM responsive to the output of the down counter provides a message signal in accordance with the residual error count remaining in the down counter. The message signal commands a bit pattern generator that applies pulse bursts controllably to the count up input or count down input of the up/down counter in accordance with the error count in the down counter so as to tend to reduce the error count in the down counter to zero.