Embedded Narrow Pulse Measurement in Digital CMOS

This paper examines an embedded low-power technique for the single-shot measurement of narrow pulse signals. The circuit serves as an embedded diagnosis tool for the characterization of compressed pulses for ultra wideband sampling schemes, pulsed radar systems, measurements of clocks with very small duty cycles, single event transients in digital circuits, among many other applications. The circuit relies on a new fast voltage-crossing detector to convert a differential input pulse with width to be characterized, into same polarity edges separated by the pulse width to be measured. Those edges are then in turn stretched further using time amplification making them easily detectable by low-resolution time-to-digital converters (TDCs). Dynamic current generation techniques are used in the front-end detector to greatly reduce the power consumption. The proposed circuit is compact and introduces only a few tens of femtoFarad capacitive loading. The circuit was implemented in a 0.18-mum CMOS process. Experimental results confirm the feasibility of the proposed technique