A Low-Power Bandgap Voltage Reference Circuit With Ultra-Low Temperature Coefficient

A highly accurate bandgap reference with ultralow sensitivity to temperature variations has been proposed. In the presented work, new techniques and circuits have been proposed to provide voltages with negative and positive temperature coefficients. Moreover, a novel fully MOS CTAT voltage generator without using BJT transistors has been proposed. This voltage and PTAT voltages with different sensitivities to temperature are finally summed up leading to the generation of a reference with a very low temperature dependency. The proposed bandgap reference has been simulated in a 0.18$\mu$m CMOS process using ADS. The temperature coefficient is almost 5 ppm$/^{\circ}\mathrm{C}$, over $-40^{\circ}\mathrm{C}$ to $100^{\circ}\mathrm{C}$ temperature variation, consuming almost 2$\mu$A quiescent current.