Low voltage bandgap reference with closed loop curvature compensation

A new low-voltage CMOS bandgap reference (BGR) that achieves high temperature stability is proposed. It feeds back the output voltage to the curvature compensation circuit that constitutes a closed loop circuit to cancel the logarithmic term of voltage V-BE. Meanwhile a low voltage amplifier with the 0.5 mu m low threshold technology is designed for the BGR. A high temperature stability BGR circuit is fabricated in the CSMC 0.5 mu m CMOS technology. The measured result shows that the BGR can operate down to 1 V, while the temperature coefficient and line regulation are only 9 ppm/degrees C and 1.2 mV/V, respectively.