MOSFETs are the go-to technology for controlling large loads from a microcontroller. While a directly driven MOSFET is fine for low power and/or low frequency PWM and for simple switching, driving the gate becomes more troublesome when using large MOSFETs with high-speed PWM. The gate of a MOSFET acts like a capacitor electrically, with the state of the transistor depending on the voltage on the gate. This has two consequences relevant to typical light electronics.

• Because the voltage on a capacitor must change over a finite period of time, there is a period of time during which the FET is neither fully on nor fully off. In this state, it will allow some current to flow, but with higher resistance - this can result in excessive heating when, for example, a heavy load is switched using PWM. Using a MOSFET with a low gate voltage helps, but does not eliminate the problem.
• Switching the FET (at least doing so quickly) requires a brief pulse of a significant current to charge or discharge the gate capacitor. For simple switching applications, a 100 ohm resistor can be placed in series with the gate (this is done on my other MOSFET breakout boards) - this, however, further reduces the switching time.

Where these issues are a problem, there's a demand for a way to apply a brief high current pulse to the gate of a MOSFET - this is known as a gate driver. These boards mount an FL3100A gate driver, which can provide up to 2.5A to the gate of the MOSFET, with rise/fall times on the order of 10nS, enabling high speed PWM of large loads. The FL1000A has a logic threshold of around 1.6v (max for high 2V, min for low 0.8V), though it requires at least 4.5v for proper operation and will apply the full operating voltage to the gate with even a low voltage signal. It provides two control pins, and only when In is high, and Dim is low will the MOSFET be turned on.

This is available assembled with a MOSFET (currently the DMTH8012, up to 80Vgs, up 50A with additional cooling is the only option - other MOSFETs may be added based on customer demand) mounted on the other side, or you can get it without the MOSFET and add the N-channel MOSFET FET of your choice.

Screw terminals are available (installed) for a small additional fee.