Low-voltage bandgap reference with temperature compensation based on a threshold voltage technique

In this paper, we describe a sub 1 V bandgap voltage reference (BGR) in CMOS technology. The proposed topology is based on a current-mode bandgap structure that uses a transimpedance amplifier. A feedback control in the bandgap produces temperature compensation between a PTAT (Proportional To Absolute Temperature) current and a CTAT (Conversely proportional To Absolute Temperature) current derived from a nMOS threshold voltage. The proposed circuit was verified by extensive circuit simulations, using models, of a standard 0.18 μm CMOS technology, with a power supply of 1 V. The variations of the output voltage over a typical temperature range (0 to 100°C) were simulated to be less than 1%.