A variable hysteresis aperturing method for superconducting counting A/D conversion

The authors present an aperturing method for superconducting counting A/D converters. The authors have given the scheme the acronym TRAP, which stands for Time Release after Aperturing of Pulses. TRAP utilizes a large β/sub L/ two-junction SQUID quantizer and plays on the ability to control the amount of hysteresis available in such a SQUID. Incoming information from the analog signal can either be immediately processed by the quantizer or trapped and output at a later time. The authors explain how this control can be used to form picosecond aperture for counting A/D converters, eliminating pulse-skipping problems. SPICE simulations confirm the ideal behavior of the TRAP