Characterization of DTMOST Structures to be used in Bandgap Reference Circuits in 0.13μm CMOS Technology

Abstract. This document describes objectives and method used to characterize DTMOST structures in the 0.13μm CMOS technology. The temperature dependence of the Id(Vgs) relationship is measured and parameterized into a simple mathematical model. On the basis of this model performances of two basic Bandgap reference (BGR) circuits have been evaluated. The classical voltage summing BGR circuit demonstrates Vref=464mV±1.25mV in the temperature range from 0oC up to 80oC when ideal opamp and current sources are used. Theoretically this circuit is capable to operate at power supply voltages (Vdd) as low as Vref+Vdssat≈ 600mV. The classical current summing BGR circuit delivers a current as well as a voltage, both remaining stable within a ±0.3% margin in the temperature range from 0oC up to 80oC when ideal opamp and current sources are used. Because of the current summing architecture theoretically this current summing BGR circuit can operate with a Vdd down to 350mV.