An oscilloscope array for high-impedance device characterization

An equivalent time oscilloscope array is implemented in a 90nm CMOS technology. A combination of adjustable termination, calibration circuitry and capacitance compensation enables driver bandwidths between 0.4 to 2GHz for termination impedances of 20Ω to 2kΩ for extraction of S-parameters and delay characteristics of high impedance devices such as carbon nanotubes (CNTs) and graphene. Measurement results show that the capacitance compensation technique enhances the bandwidth by 3X for impedances between 2kΩ and 20kΩ.