High-speed differential resistor ladder for A/D converters

This paper describes the implementation of a novel high-speed differential resistor ladder suited for A/D converters. The novel ladder yields, theoretically, up to a sixteen-fold reduction of the propagation delay with respect to the conventional differential ladder. Simulation results, for a BiCMOS 0.25μm technology, show that the novel ladder results in a fivefold increase of the maximum sampling frequency when employed to design a 8-bit Flash converter. A 70% higher speed is also highlighted when the ladder is employed in a Folding and Interpolating 8-bit converter.