Temperature Effects on the Electrical Characteristics of BJTs and MOSFETs

Abstract

The aim of the present paper is to shed further light on studying the temperature effects on the static (I-V) and dynamic (C-V) characteristics of bipolar junction- and metal oxide field effect - transistors. In this concern, several parameters were plotted at different temperature levels. The experimental results showed that, for the bipolar junction transistor 2SC2120, a noticeable increase in the collector current and the current gain from 0.198 A and 0.14 up-to 0.25 A and 0.24 by increasing the temperature from 25oC and 135oC, respectively. Considering the threshold voltage, its value was shown to be decreased from 0.62 Volt to 0.42 Volt within the same temperature range. In addition, from the traced dynamic characteristics of the same BJT, the diffusion capacitance of the emitter-base junction, as an example, increased from 10.11 nF up-to 45.09 nF by increasing the temperature up-to 135 oC. On the other hand, for metal oxide field effect transistor 2N6660, the static characteristics showed that a noticeable decrease in the drain current and the forward trans-conductance from 1.2A and 5.0 Ω-1 down-to 0.79 A and 1.9 Ω-1, respectively, due to temperature increasing from 25 oC up-to 135 oC. While the threshold voltage was hold constant. Finally, the reverse capacitance of the gate-drain junction was shown to be increases from 41.48 pF up-to 47.31 pF within the same range of temperature.