An improved analogue front-end for measuring the high state of trapezoidal voltage pulses with transition duration of 3 μs is presented. A new measurement system, composed by a front-end and the state-of-the-art acquisition board NI PXI-5922, has been realized with improved Common Mode Rejection Ratio (CMRR) of more than 87 dB at DC and 3-sigma stability of }0.65 ppm over 1 day. After highlighting the main design enhancements with respect to state-of-the-art solutions, the CMRR measurement is reported. The output drift due to temperature and humidity is assessed to be negligible. Finally, the worst-case repeatability is measured both with shorted-to-ground inputs and with an applied common-mode voltage of 10 V, which represents the nominal working condition. An improved analogue front-end for measuring the high state of trapezoidal voltage pulses with transition duration of 3 µs is presented. A new measurement system, composed by a front-end and the state-of-the-art acquisition board NI PXI-5922, has been realized with improved Common Mode Rejection Ratio (C M RR) of more than 87 dB at DC and 3-sigma stability of ±0.65 ppm over 1 day. After highlighting the main design enhancements with respect to state-of-the-art solutions, the C M RR measurement is reported. The output drift due to temperature and humidity is assessed to be negligible. Finally, the worst-case repeatability is measured both with shorted-to-ground inputs and with an applied common-mode voltage of 10 V, which represents the nominal working condition. C 2015 AIP Publishing LLC.[http://dx