A Sub-1 ppm/°C Precision Bandgap Reference With Adjusted-Temperature-Curvature Compensation

This paper presents a precision bandgap reference with an innovative adjusted-temperature-curvature compensation circuit that obtains a good temperature coefficient (TC) over a wide temperature range. The proposed compensation circuit for enhancing the voltage accuracy of the bandgap reference combines an addition circuit, subtraction circuit, and current mirror to achieve an adjusted piecewise linear temperature current over an entire temperature range. The proposed bandgap reference was designed and fabricated using a standard Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 mu m 1P6M CMOS technology. Measurements on eight samples indicated that the proposed bandgap reference achieved a TC that varies from 1.67 to 10.55 ppm/degrees C from -40 degrees C to 140 degrees C with a supply voltage of 1.8 V. The measured 547 mV reference voltage achieved a precision line regulation that is less than 0.08%/V for supply voltages between 1.3 and 1.8 V. The proposed circuit dissipated 28 mu A with a supply voltage of 1.8 V, and an active area of 0.0094 mm(2). The circuit was designed to operate on a low supply voltage down to 1.3 V.