A High Precision Curvature Compensated Bandgap Reference without Resistors

This paper describes a low offset high precision curvature compensated bandgap reference in a 0.5-mum n-well CMOS technology without resistors. This bandgap reference employs an inverse function voltage transfer cell rather than conventional resistors, together with a low-noise and low-offset scheme to provide a temperature independent gain. Cascode structures are also introduced in order to improve the power supply rejection ratio (PSRR). The effective temperature coefficient of the bandgap reference is 6 ppm/degC. The variation in the output voltage of the bandgap reference is 1.2 mV when Vdd varies from 4.5 V to 5.5 V. The power dissipation is 2.5 mW at 5 V power supply