High-current gate-driver devices are required in switching power applications for a variety of reasons. In order to effect fast switching of power devices and reduce associated switching power losses, a powerful gate driver is employed between the PWM output of controllers and the gates of the power-semiconductor devices. Further, gate drivers are indispensable when there are times that the PWM controller cannot directly drive the gates of the switching devices. With advent of digital power, this situation is often encountered because the PWM signal from the digital controller is often a 3.3-V logic signal, which is not capable of effectively turning on a power switch. A level-shifting circuitry is needed to boost the 3.3-V signal to the gate-drive voltage (such as 12 V) in order to fully turn on the power device and minimize conduction losses. Because traditional buffer-drive circuits based on NPN/PNP bipolar transistors in totem-pole arrangement, being emitter-follower configurations, lack level-shifting capability, the circuits prove inadequate with digital power.

Gate drivers effectively combine both the level-shifting and buffer-drive functions. Gate drivers also find other needs such as minimizing the effect of high-frequency switching noise by locating the high-current driver physically close to the power switch, driving gate-drive transformers and controlling floating power-device gates, reducing power dissipation and thermal stress in controllers by moving gate-charge power losses into itself. Finally, emerging wide-bandgap power-device technologies, such as GaN based switches, which are capable of supporting very high switching frequency operation, are driving very special requirements in terms of gate-drive capability. These requirements include operation at low V_DD voltages (5 V or lower), low propagation delays and availability in compact, low-inductance packages with good thermal capability. In summary gate-driver devices are extremely important components in switching power combining benefits of high-performance, low cost, component count and board space reduction with a simplified system design.