Sandia LabNews

Novel chip counts time intervals to the trillionths

Ken Condreva (8416) has built a better stopwatch. It’s smaller than a dime, accurate to 125 picoseconds, and can be produced far more inexpensively than comparable devices.

The inspiration for his invention was the need to accurately record critical timing signals in weapon test flights, beginning 10 years ago. New telemetry systems required a compact, lightweight, and low-power device for this purpose.

"The only things I could find that had this resolution were table-top instruments packaged in a box," Ken said. "They were way too big, and used way too much power."

His invention became the FALCON, an integrated circuit that uses his patented "Pulse Stretcher" technique to increase resolution up to 200 times for a low-power electronic clock (using 300 mW at 40 MHz). The circuitry provides greater resolution by lengthening duration of the output signal, making it last from 64 to 200 times longer than the input signal. Although the input pulse is "stretched" in real time, the technique can be compared to recording a sporting event with fast-action film and replaying it at slow speed to clearly see what happened.

Reasoning that a compact way to count time intervals at high resolution with low power would be useful commercially, Ken obtained a patent in 1994.

Applications are in areas that rely on measuring distances accurately, such as land surveying; construction; testing, assembly, and manufacturing; liquid level measurements in chemical or petrochemical plants; and collision warning and avoidance in vehicles, says business developer Scott Vaupen (8709).

This timing device accurately operates not only in "normal" working conditions, but also in extremely rugged and harsh environments — high and low temperatures, high vibration and shock, as well as high and low humidity. Small and inexpensive battery-operated monitors could also be devised for future innovative uses.

The integrated circuit uses standard commercially available CMOS technology and could be inexpensively manufactured by most semiconductor businesses, Scott says.

Sandia is currently seeking commercialization partners with imagination to exploit what it considers to be a robust and innovative technology.