Design of a BiCMOS integrated temperature sensor proportional to absolute temperature

Proportional to absolute temperature (PTAT) BiCMOS integrated temperature sensor was designed by applying the index characteristics of a MOSFET transistor saturated drain current, which worked on weak inversion region. The main circuit was composed by three parts, which were PTAT current generating circuit, start-up circuit and output circuit. The circuit had the advantages of simple structure and small volume. The tested results indicated that the accuracy of the integrated temperature sensor was within 0.5°C, the linearity was within 0.65%, the sensitivity was 2.5 μA/°C and the area of the chip was 150 m×75 m The integrated temperature sensor had higher linearity and sensitivity which could be widely applied to various kinds of portable electronic products.