A design method of bipolar junction transistor for high-precision remote temperature sensing

A design method of BJTs for high-precision temperature-sensing is studied. The effects of non-idealities in the BJT on temperature-sensing accuracy are analyzed, and an accuracy evaluation formula containing the nonidealities is derived. We have proposed a novel parameter criteria of high-precision temperature-sensing BJT which constrains the influenced error of each non-ideality below +/- 0.1 C using the variable-controlling procedure. The conversion approach from the proposed parameter criteria to electrical characteristics is also developed to guide the high-precision temperature-sensing BJT design. According to the proposed method, temperature-sensing BJTs are designed and fabricated. The test results showed that the temperature-sensing accuracy is within +/- 0.5 C in temperature range of -55 degrees C to 125 degrees C, which meets the need for highprecision temperature sensing.