Test structure for I/sub C/(V/sub BE/) parameter determination of low voltage applications

The temperature dependence of the I/sub C/(V/sub BE/) relationship can be characterised by two parameters: E/sub G/ and X/sub TI/. The classical method to extract these parameters consists in a "best fitting" from measured V/sub BE/(T) values, using least square algorithm at constant collector current. This method involves an accurate measurement of Y/sub BE/ voltage and an accurate value of the operating temperature. We propose in this paper, a configurable test structure dedicated to the extraction of temperature dependence of I/sub c/(V/sub BE/) characteristic for BJT designed with bipolar or BiCMOS processes. This allows a direct measurement of die temperature and consequently an accurate measurement of V/sub BE/(T). First, the classical extraction method is explained. Then, the implementation techniques of the new method are discussed, the improvement of the design is presented.