A Fully Integrated 5510-μm² Process Monitor and Threshold Voltage Extractor Circuit in 28 nm

A new architecture of an on-die process monitor circuit is demonstrated in 28 nm. The proposed circuit can extract the threshold voltage, $V_{\mathrm { TH,}}$ and random mismatch of a transistor using multiple extraction methods, including the second derivative method. A sigma-delta modulator analog-to-digital converter samples the output to enable on-die processing of the results. A $V_{\mathrm { DS}}$ voltage control loop enables $V_{\mathrm { TH}}$ extraction in both the linear and saturation regions of the device. The circuit has a compact area of $5510~\mu $ m2.