Study on temperature effect on p-n and zener junction for PTAT temperature sensor
P. Songmalai, Toempong Phetchakul, Weera Pengchan, Eakkarach Ratanaudomphisut, Jakrapong Supadech · 2008
Research on a new compact BJT PTAT temperature sensor structure has been reported. The zener junction-connected BJT transistor and Base-Emitter voltage of transistor can be temperature dependent. The performance of new compact PTAT circuit can be improved by using difference in thermal characteristics between p-n and zener junction. DeltaV/DeltaT can be further increased by connecting p-n and zener junction in series. The results show that DeltaV/DeltaT of the circuit increased by 6.77 timed or 85% compared with conventional PTAT and connecting two p-n and zener junction in series. The result show that DeltaV/DeltaT of the circuit increased by 3.3 timed or 70%compared with proposed circuit the output voltage is large enough so that it can be used directly without additional amplifier. This also improves S/N ratio and the unique linearity of PTAT is still preserved. The working temperature of circuit is between - 60degC to 160degC.