A 1.9μVrms 7.7ppm/°C ADC Reference with 20mA Output Current and Single-Trim Inaccuracy of ±0.03%(3σ) from -40°C to 125°C

This work presents a high-precision low-drift voltage reference for ADC beyond 14bits. Combining a chopper-stabilized bandgap reference (BGR) and a ping-pong auto-zeroing LDO, the reference achieves $1.9\mu \mathrm{V}_{\mathrm{r}\mathrm{m}\mathrm{s}}$ (0.1-10Hz BW) noise while supporting dynamic loads with a maximum output current of 20mA. A multisegment compensation optimizes the temperature coefficient (TC) curvature and significantly reduces high-order voltage drift due to both convex and concave curves. Fabricated in a 40nm CMOS LP process, the proposed voltage reference achieves an average TC of $7.7\mathrm{p}\mathrm{p}\mathrm{m}/{}^{\circ}\mathrm{C}$ (10 samples) and an initial inaccuracy of $\pm 0.03\%(3\sigma)$ from $-40^{\circ}\mathrm{C}$ to $125^{\circ}\mathrm{C}$ with 1-point trim.