A low drift curvature-compensated bandgap reference with trimming resistive circuit

A low temperature drift curvature-compensated complementary metal oxide semiconductor （CMOS） bandgap ref- erence is proposed. A dual-differential-pair amplifier was employed to add compensation with a high-order term of TInT （T is the thermodynamic temperature） to the traditional 1 st-order compensated bandgap. To reduce the offset of the amplifier and noise of the bandgap reference, input differential metal oxide semiconductor field-effect transistors （MOSFETs） of large size were used in the amplifier and to keep a low quiescent current, these MOSFETs all work in weak inversion. The voltage reference＇s temperature curvature has been further corrected by trimming a switched resistor network. The circuit delivers an output voltage of 3 V with a low dropout regulator （LDO）. The chip was fabricated in Taiwan Semiconductor Manufacturing Company （TSMC）＇s 0.35-gm CMOS process, and the temperature coefficient （TC） was measured to be only 2.1× 10^-6/℃ over the temperature range of-40-125℃ after trimming. The power supply rejection （PSR） was -100 dB @ DC and the noise was 42 μV （rms） from 0.1 to 10 Hz.