Substrate leakage current influence on bandgap voltage references in automotive applications

This paper presents a study of the influence of the substrate leakage current on the output voltage of a well-known bandgap architecture with second order compensation. In addition, an analytical approach for the output voltage is provided. The bandgap voltage reference has been successfully implemented in a standard BiCMOS technology on an effective area of 0.07mm². A low quiescent current of 4μA and a very small variation of the output voltage have been achieved over the whole temperature range by eliminating the effect of the leakage current. Therefore, a variation of 3mV has been measured for the whole operating temperature range (-40°C to 170°C).