An Improved High-Order Temperature Compensation Bandgap with Linearized VBE

Abstract

This paper proposes an improved high-order compensation bandgap reference (BGR) for high-precision applications, addressing the limitations of traditional linearized VBE in accurately modeling high-order temperature nonlinearity. The circuit consists of a bandgap circuit, a start-up circuit, and a trimming circuit. A zero temperature coefficient (TC) current flowing through the high-order compensation Bipolar Junction Transistor (BJT) is guaranteed by adding an operational amplifier (op-amp). Reasonable design and a trimming circuit make the high-order compensation branch current equal to the proportional-to-absolute-temperature (PTAT) current. The proposed BGR is fabricated with a 0.18-μm process, with a supply voltage of 1.8 V, and has the layout area of 220 × 123 μ m². Measurement results show a TC of 5.19 ppm/℃ over the -40℃ to 125℃, a Line Regulation (LR) of 0.2632% for supply voltage from 1.55V to 2V, and a power consumption of 159.21 μW.