Operation of practical eSFQ circuits

We have designed and tested energy-efficient single flux quantum (eSFQ) circuits for use in practical circuits. The first circuit is a 184-bit shift register for acquisition memory to store short transient events. The second circuit is a 16-bit deserializer integrated with an analog-to-digital converter modulator. The deserializer converts a high speed oversampling delta modulator 1-bit data stream into 16 parallel digital outputs at 1/16 of input data rate. In this work, we report preliminary functional and high-speed operation of some of these eSFQ circuits including their margins of operation at different clock speeds, maximum operation frequencies, and power dissipation.