Low-voltage CMOS VT extractor

A new and accurate MOS threshold voltage (V_T) extractor is proposed. The principle of operation is based on a novel negative feedback that reduces the effects caused by second-order factors and supply voltage variations. The advantages of the circuit against previous implementations are true low-voltage supply operation and low current consumption capabilities. Simulation results, based on the 0.35 mum AMS BiCMOS process, demonstrate a variation of less than 0.3% of the extracted value of V_T for a supply voltage in the range 1-3.6 V.