Abstract
IR-drop monitoring has been an effective means to assess the power integrity in real silicon. Existing methods, however, fail to achieve a high accuracy and a high sampling rate simultaneously. In this work, we present a novel method to resolve this dilemma. First of all, we focus on the measurement of the worst-case IR-drop, instead of the entire sampled VDD waveform. This strategy can make a high sampling rate more viable. Secondly, periodic calibration can be supported to account for the process variation and the temperature change if needed. Another benefit of the proposed method is that it can be designed using only standard cells. Test chips have been fabricated and measurement results demonstrate that this method can support a sampling rate of more than 1 GHz, while achieving an average measurement error of 3.05 mV, and a worst-case measurement error of 8.23 mV.