CMOS bandgap with base-current thermal compensation

This paper describes a CMOS bandgap voltage reference, which features a curvature compensation that is based on the thermal behavior of the base current. The core of the circuit uses vertical bipolar transistors and high resistive poly resistors (RPOLYH), as most currently implemented CMOS bandgap circuits, however arranged in a novel configuration. A three-bit digital trimming mechanism was incorporated in the circuit to adjust the reference voltage to its minimum TC value. Samples of the circuit were fabricated in 0.6 /spl mu/m CMOS. Measurements in the range -40/spl deg/C to +120/spl deg/C showed that the temperature drift is less than 23 ppm//spl deg/C.