The high-speed capability of superconductive electronics is being harnessed
to develop a time-to-digital converter (TDC) with picosecond time resoluti
on. We have designed and successfully tested prescaler circuits for improvi
ng TDC resolution first to 5 ps, and then below. These circuits are designe
d to act as a vernier for a superconductive TDC that counts clock periods u
sing a binary counter. One prescaler circuit has already demonstrated 5 ps
resolution at a clock frequency of 20 GHz.