Objective

The objective of this laboratory is to demonstrate the switching behaviour of a MOSFET Enhanced N-Channel by switching a lamp ON and OFF.

Preparation

The following schematic details the hardware setup.

Table 1 lists the components used in the schematic.

IDComponentManufacturer Part No.ValueQty.
IC1MOSFET Enhanced N-ChannelSTP60NF06–1
LA1LampJKL Components 3166.0V1
Table 1: Components
Testing

The MOSFET Enhanced N-Channel used in this laboratory is specifically designed for switching, not amplification. Figure 1 represents measured currents from the Source-to-Drain terminals at various Gate-to-Source voltages.

Figure 1: Drain Current VS. Gate Voltage

It can be seen that at a Gate-to-Source voltage of approximately 3.6V, current starts to flow from the Drain to Source terminals. This voltage represents the Gate-to-Source threshold voltage, which sits in between the voltage range as per the datasheet, i.e., 2 to 4V. At this voltage, the globe’s filament may not illuminate at all, despite a current flowing from the Drain to Source terminals. Increasing the Gate-to-source voltage reveals a sharp increase in the drain-to-source current flow until it stabilises at around 0.320 Amps, in which case the transistor is ON. At this voltage, the globe’s filament will illuminate brightly.

Figure 2 represents measured voltages from the Drain-to-source terminals at various Gate-to-Source voltages.

Figure 2: Drain Voltage VS. Gate Voltage

It can be seen that at a Gate-to-Source voltage of approximately 3.6V, the voltage between the Drain and Source terminals starts to drop. Increasing the Gate-to-source voltage further reveals a sharp decrease in the Drain-to-Source voltage, indicating less resistance between the two terminals.

Figure 3 represents measured currents from the Drain-to-Source terminals at various Drain-to-Source voltages.

Figure 3: Drain Current VS. Drain Voltage

It can be seen that as the Drain-to-Source voltage increases, the resistance and current between these terminals increase and decrease, respectively. Increasing the Drain-to-Source voltage further reveals a gradual decrease in the Drain-to-Source current until it stabilises at around 0A, in which case the transistor is OFF.

Conclusion

Based on measurements and the behaviour of the MOSFET, it is functioning as expected and can therefore be used as the basis of projects.