A low temperature drift bandgap reference source with piecewise temperature compensation

A bandgap reference with wide temperature range and low temperature drift coefficient is proposed. With the bandgap reference of Banba structure as the core circuit, the parabolic output reference voltage with an opening downward is generated, the parabola vertex is moved to the high temperature section, the high temperature section of the output reference voltage tends to be smooth, and the piecewise temperature compensation technique is used to compensate the curvature of the low temperature section, and the compensation current is generated by current subtraction with different temperature coefficients, which effectively reduces the temperature drift coefficient and broadens the temperature range of the bandgap reference. The circuit performance is verified under the standard 0.18 μm CMOS process. The simulation results show that the temperature drift coefficient of the proposed bandgap reference is 0.65 ppm/℃ in the temperature range of −50 to 150℃, the output voltage is 760 mV under the power supply voltage of 1.8 V, and the layout area is only 0.01 mm².