A 2.69 ppm/°C Bandgap Reference with 42 ppm/V Line Sensitivity for Battery Management System

This paper presents a high-precision bandgap reference (BGR) with an ultra-low temperature coefficient (TC), line sensitivity (LS) and designable reference voltage for battery management system (BMS) applications. A low dropout regulator (LDO) is employed at the output to compensate for the limited driving capability of the current-mode BGR, while a pre-regulator circuit is implemented to improve its LS. In order to achieve a low TC, piecewise curvature compensation is used to compensate for the higher-order nonlinearity of the $V_{\mathrm{BE}}$ voltage, and two-point trimming at $20^{\circ} \mathrm{C}$ and $60^{\circ} \mathrm{C}$ is used to ensure the effectiveness of piecewise curvature compensation under batch trimming. The BGR was implemented in a 180 nm process with an active area of $0.548 \mathrm{~mm}^{2}$. Measurement results indicate that this BGR has an output voltage of 2.5 V and consumes $84 \mu \mathrm{~A}$ of current at a 5 V supply voltage. An average TC of $2.69 \mathrm{ppm} /{ }^{\circ} \mathrm{C}$ with two-point trimming over the temperature range of $-40{ }^{\circ} \mathrm{C}$ to $125{ }^{\circ} \mathrm{C}$. The proposed BGR can deliver a load current of 1 mA with an LS of $0.0042 \% / V$.