A Sub-1 ppm/°C Bandgap Voltage Reference With High-Order Temperature Compensation in 0.18-μm CMOS Process

This paper presents a high-precision bandgap voltage reference (BGR) with high-order temperature compensation. The compensation signal is generated by using both strong-inversion MOSFETs and Bipolar Junction transistors (BJTs), which cancels the high-order nonlinear term $T\ln (T)$ in the BJT base-emitter voltage (V _BE ), and thus a low temperature coefficient (TC) over a wide temperature range is achieved. The proposed BGR circuit is fabricated in a 0.18- $\mu \text{m}$ CMOS process with an active area of $0.256 m{m^{2}}$ and a max power consumption of 1.35 mW. A minimum TC of 0.706 ${\mathrm{ppm}}/{}^ \circ C$ from $- 25\,\,{}^ \circ C$ to 125 ${}^ \circ C$ is achieved after an 8-bit resistance trimming. The line sensitivity is 0.0146%/V operating from 3.2 V to 3.7 V. The BGR achieves a power supply rejection (PSR) of −63.4 dB and a noise spectrum density of $0.92 ~\mu \text{V}/\sqrt {Hz} $ at 10 Hz.