A high-precision bandgap reference with -0.063 ppm/°C temperature coefficient in a 45 nm CMOS process

Official URL: https://dx.doi.org/10.1109/ELECO69582.2025.11329327

This study presents the design, device characterization, and simulation of a Bandgap Reference (BGR) circuit using 45nm CMOS technology. Three vertical pnp transistors with varying silicon areas were characterized to select an optimal device for CTAT generation. The PTAT generator's resistor ratios were optimized over a -40 °C to 125 °C temperature range to achieve first-order cancellation. A schematic-level BGR was developed by combining both CTAT and PTAT, incorporating a startup circuit to prevent the BGR from settling into a zero-current state. The final design achieves an output voltage of approximately 1.63 V with an exceptional temperature coefficient of -0.063 ppm/°C. The primary contribution of this work is achieving ultra-high thermal stability without the use of explicit, complex curvature-compensation circuitry, relying instead on the inherent cancellation of second-order effects through systematic device selection. This represents a deliberate trade-off, prioritizing exceptional thermal stability over low-voltage compatibility and area efficiency.