Antiphon said:Yes, the FET with negative feedback from drain to gate makes an excellent linear resistor with gate voltage. The impedance will not be super high due to tge negative feedback network but it's plenty high enough to be driven by analog ICs. The ohmic range will extend from near zero to near open circuit.
A transistor can function as a variable resistor by controlling the amount of current that flows through it. By adjusting the base-emitter voltage, the resistance of the transistor can be varied, allowing for a range of current flow.
The advantage of using a transistor as a variable resistor is that it is a more precise and efficient method compared to using a traditional variable resistor. Transistors have a higher range of resistance and can handle larger currents, making them useful for a variety of applications.
Transistors as variable resistors are commonly used in electronic devices such as amplifiers, oscillators, and voltage regulators. They can also be found in industrial control systems, power supplies, and audio equipment.
No, not all transistors can function as variable resistors. Only certain types, such as bipolar junction transistors (BJTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs), have the ability to vary their resistance based on the input voltage.
One limitation of using a transistor as a variable resistor is that it can only handle a certain amount of power before it becomes damaged. Additionally, the resistance range may be limited, and the accuracy may be affected by factors such as temperature and aging of the transistor.