Current and voltage ADC using a differential pair of single-electron bipolar avalanche transistors

Single-electron bipolar avalanche transistors (SEBATs) enable current sensing by electron counting at room temperature. Here, differential SEBAT circuits combining the functions of amplification and analog-to-digital (A/D) conversion are proposed and characterized for two applications: Low-current AID conversion and differential voltage A/D conversion. Charge detection efficiencies in the order of 30% are reached, allowing for the direct A/D conversion of currents in the 10(-13) A range. An equivalent of the differential pair is used as a differential voltage ADC.