In the context of transistors, the terms "negative temperature coefficient," "positive temperature coefficient," and "linear voltage coefficient" refer to the relationship between temperature changes and certain electrical properties of the transistor. Here's a brief explanation of each:
Negative Temperature Coefficient (NTC): A transistor exhibits a negative temperature coefficient when its electrical property decreases as temperature increases. In other words, as the temperature rises, the value of the property decreases. For example, an NTC transistor might have a decrease in gain (amplification) or a decrease in conductivity as the temperature increases.
Positive Temperature Coefficient (PTC): Conversely, a transistor demonstrates a positive temperature coefficient when its electrical property increases as temperature increases. This means that as the temperature rises, the value of the property also increases. For instance, a PTC transistor might show an increase in gain or conductivity as the temperature increases.
Linear Voltage Coefficient: The linear voltage coefficient, also known as the temperature coefficient of voltage, refers to the change in output voltage of a transistor due to temperature variations. It describes the relationship between temperature changes and the output voltage level of the transistor. A linear voltage coefficient indicates that the change in output voltage is proportional to the temperature change. If the coefficient is positive, the output voltage increases with temperature, while a negative coefficient means the output voltage decreases with temperature.
These different coefficients play a role in understanding the behavior of transistors under varying temperature conditions and can have implications for their performance and stability in electronic circuits. Circuit designers and engineers take these coefficients into account when designing and selecting transistors for specific applications to ensure proper functioning and temperature compensation.