Voltage reference circuit play a vital role in analog circuits. A reference voltage is expected to be high precision and insensitive to power supply, process and temperature variation. An improved piecewise curvature-corrected bandgap voltage reference (BGR) with low temperature coefficient and better line regulation was designed in this research work. The proposed BGR consisting of piecewise curvature-corrected circuit was implemented in $0.18-\mu \mathrm{m}$ CMOS process. At DC supply of 1.8 V, the piecewise curvature-corrected BGR can function properly with output reference voltage of 549.0 mV to 550.2 mV by varying supply voltage of 1.8 V to 3.0 V. The best temperature coefficient that can be achieved is 3.83 ppm/ °C with temperature of $-25^{\circ}\mathrm{C}$ to $70^{\circ}\mathrm{C}$ at a supply voltage of 1.8 V. The proposed piecewise curvature-corrected bandgap voltage reference is able to function properly with high precision, which is ready to be fabricated. It is suitable module for applications such as ADC, DAC, voltage regulators and PLL.

Design and simulation of Piecewise Curvature-Corrected Bandgap Reference Circuitry for low temperature coefficient

A 3.3 V CMOS bandgap reference (BGR) was presented in this study that utilizes MOS transistors operating in the sub-threshold region. The complexity of the circuit and the dependency of the voltage reference on power supply variations are simultaneously decreased through the use of a new compensation circuit technique. The proposed BGR is simulated using a 0.35 $\mu \mathrm{m}$ CMOS standard process. Consequently, a 5.53 ppm/°C temperature coefficient is obtained in the -40~+125 °C temperature range, the maximum power supply rejection ratio is - 62 dB, and a 2.033 mV/V voltage line regulation is achieved for the $2.3\sim 4.3$ V supply voltage. The proposed circuit dissipates a supply current of 8.89 IJA at a 3.3 V supply voltage, and the active area is 112 $\mu \mathrm{m}\times 60 \mu \mathrm{m}$.

Jae-Kun Kim

Papers

A 3.3 V, 8.89 μA and 5.5 ppm/°C CMOS bandgap voltage reference for power telemetry in retinal prosthesis systems