A prescaler circuit for a superconductive time-to-digital converter

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