A 15uW, 12 ppm/^°C Curvature Compensated Bandgap in 0.85V Supply

Abstract

In this paper, a curvature-compensated bandgap reference circuit is presented which generates 0.538V from 0.85V supply voltage. The PTAT voltage generated in the bandgap core is added to the partial CTAT voltage to generate the sub-bandgap reference, reducing the CTAT current mirror mismatch. Furthermore, this architecture eases the opamp's requirements on offset and flicker noise significantly and doesn't require sophisticated techniques, such as chopping. A novel curvature compensation scheme is proposed and validated across PVT simulations and achieves 12 ppm/°C with a single point trim. The proposed bandgap consumes a power of 15 μW and occupies an area of 7315 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> in TSMC 28nm.