Floating-Gate Transistor Physics The floating-gate transistor (FGT) is a special type of transistor that uses the electric field in the channel between the s...
The floating-gate transistor (FGT) is a special type of transistor that uses the electric field in the channel between the source and drain to control the flow of charge carriers, thereby affecting the overall behavior of the device. This behavior is different from traditional bipolar transistors, where the base and collector are connected directly to the voltage source.
The FGT operates based on the principle of controlling the potential difference between the source and drain. When a positive voltage is applied to the source and a negative voltage is applied to the drain, the FGT becomes conductive, allowing a flow of charge carriers from the source to the drain. The width of the channel and the applied voltage determine the amount of current that flows between the source and drain.
The key feature of the FGT is that the gate voltage is separate from the source and drain voltage. This allows the FGT to be controlled independently, enabling precise control over the device. This property makes the FGT ideal for various memory designs, including DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory).
Example:
Imagine a single transistor with the source and drain connected to a power supply and the gate connected to a reference voltage. When a positive voltage is applied to the source and a negative voltage is applied to the gate, a current will flow from the source to the drain, indicating that the transistor is conducting. This is how the FGT's control voltage works