Gate Driver Circuit
It is the intermediate layer standing between the microcontroller's milliampere-level logic output and the gate of the power MOSFET. It shortens the transition by charging and discharging the gate capacitance with a pulse current in the ampere range; it typically supplies 1–4 A peak current and completes the transition in the range of hundreds of nanoseconds.
The gate of a power MOSFET electrically looks like a capacitor of a few nanofarads. The faster you charge this capacitor, the faster the MOSFET turns on. A gate connected directly to a microcontroller pin stays in the partial-conduction region for microseconds because of the pin's 20–40 mA limit, and during this time the switch heats up like a resistor.
The gate driver solves this problem in two ways: it supplies a high pulse current, and it produces the above-supply voltage required for the high-side switches (usually by the bootstrap method). Typical integrated drivers provide 1–4 A peak current and bring the transition time down to the 50–300 ns range.
This layer is not seen by the user but its results are: a poorly driven power stage heats up far more at the same current and cannot withstand high switching frequency. A driver module's ability to really carry the continuous current it declares depends largely on this layer being designed correctly.
The context in which this term is used: DC Motor Driver Selection Guide