A measure of the gain of an active device, calculated by dividing the variation in output current by the corresponding variation in input voltage. Denoted by the symbol gm and measured in siemens or mhos, it is a fundamental parameter in designing amplifier circuits using field-effect transistors and vacuum tubes.
The transconductance of this MOSFET drops off significantly when it heats up, which shifts our bias point.
In practical bench work with tubes or FETs, a higher transconductance means the device can drive more current for a given input signal, making it more sensitive but also more prone to oscillation if not carefully bypassed.
Also heard as
- mutual conductance
- gm
Related terms
MOSFET
A metal-oxide-semiconductor field-effect transistor is a voltage-controlled switch used to amplify or switch electronic signals.
Gain
A measure of a circuit's ability to increase the power or amplitude of a signal.
Amplifier
A circuit or standalone device that increases the power, voltage, or current of an electrical signal.