A 1.31-ppm/ ° C CMOS Voltage Reference With Second-Order and Sub-Ranging Compensation

This article presents a high-order compensation voltage reference with a low temperature coefficient (TC) over a wide temperature range for the high-precision signal processing circuits. By using a shunt resistor in the current-mode bandgap reference, a nonlinear PTAT current for second-order temperature compensation is achieved. Besides, the sub-ranging high-order compensation is applied in the voltage reference to obtain a lower TC. The proposed voltage reference was designed and fabricated in a standard 180-nm CMOS technology. The proposed voltage reference achieves an average TC of 1.31-ppm/<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∘</sup>C after one-point batch trimming from -40 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∘</sup>C to 90 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∘</sup>C. It consumes 28 μA at 27 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∘</sup>C and occupies an area of 0.075 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>.