  It has been suggested that Rapid Single Flux Quantum (RSFQ) devices could be
used as the classical interface of superconducting qubit systems. One problem
is that the interface acts as a dissipative environment for a qubit. Recently
ways to modify the RSFQ damping to reduce the dissipation have been introduced.
One of the solutions is to damp the Josephson junctions by a
frequency-dependent linear circuit instead of the plain resistor. The approach
has previously been experimentally tested with a simple SFQ comparator. In this
paper we perform experiments with a full RSFQ circuit, and thus conclude that
in terms of stable operation the approach is applicable for scalable RSFQ
circuits. Realisation and optimisation issues are also discussed.
