부산대학교 도서관

The total-ionizing-dose (TID) radiation tolerance of bandgap references in deep-submicron CMOS technology is generally limited by the radiation introduced leakage current in diodes. An analysis of this phenomenon is given in this paper, and a dynamic base leakage compensation (DBLC) technique is proposed to improve the radiation hardness of a bandgap reference built in a standard 0.13 $\mu{\rm m}$ CMOS technology. A temperature coefficient of 15 ${\rm ppm}/^{\circ}{\rm C}$ from $-40^{\circ}{\rm C}$ to 125$^{\circ}{\rm C}$ is measured before irradiation. The voltage variation from 0$^{\circ}{\rm C}$ to 100$^{\circ}{\rm C}$ is only $\pm$ 1 mV for an output voltage of 600 mV. Gamma irradiation assessment proves that the bandgap reference is tolerant to a total ionizing dose of at least 4.5 MGy. The output reference voltage exhibits a variation of less than 3% during the entire experiment, when the chip is irradiated by gamma ray at a dose rate of 27 kGy/h.