A 4.6-ppm/°C High-Order Curvature Compensated Bandgap Reference for BMIC

This brief presents a high precision high-order curvature-compensated bandgap voltage reference (BGR) with a 3.11-V output voltage for battery-management integrated circuits. The proposed circuit utilizes the exponential characteristics of the base current and the resistance between bases of bipolar transistors to perform corrections. The curvature of subthreshold-operating MOSFETs is considered to further compensate for high-order temperature effects over a wide temperature range of 170 degrees C. Test results for the proposed BGR fabricated utilizing a standard 0.18-mu m BiCMOS process demonstrate that its line regulation is approximately 0.31 mV/V in a supply voltage range of 4.2-6.0 V. with 4-bit trimming, a temperature coefficient of 4.6 ppm/degrees C is obtained in the range of -40 degrees C to 130 degrees C. The active area of the proposed BGR is 634 x 351 mu m.