The feedforward ΔΣ ADC employing an adder comparator

This paper presents the implementation of analog signal adder in the feedforward delta-sigma A/D converters, which offers a wide signal bandwidth. An analog signal adder employing the current-mode addition is introduced and the adder comparator including the adder is described. This study examines the functionality and feasibility of the adder comparator in the delta-sigma ADC. The circuit simulation results show that the ADC offers a very compatible performance similar to those that use the ideal adder. Based on the depth analysis of circuit non-ideality of the adder, the ADC is highly tolerable to non-ideal characteristics that arise from process variation/circuit imperfections.