An isolated gate driver is a special category of driver normally used for high-power (kilowatt) applications. Primary functions include boosting the strength of the microcontroller (or DSP) output signal, increasing the voltage swing from 3.3 V up to +18 V (and sometimes to -5 V during turn-off), and raising the current level from 3 mA to 3 A or more. Secondly, a gate driver provides the high current necessary to quickly turn on (charge) and turn off (discharge) an IGBT or MOSFET power device. Finally, gate drivers deliver good isolation, separating the low-level microcontroller output signals from the DC bus voltage (often called DC Link).