JAJSRH6E February 2010 – November 2023 UCC27321-Q1 , UCC27322-Q1
PRODUCTION DATA
High-current gate driver devices are required in switching power applications for a variety of reasons. To enable fast switching of power devices and reduce associated power losses, a powerful gate driver can be employed between the PWM output of controllers or signal isolation devices and the gates of the power semiconductor devices. Further, gate drivers are indispensable when sometimes it is just not feasible to have the PWM controller directly drive the gates of the switching devices. The situation may be encountered because the PWM signal from a digital controller or signal isolation device is often a 3.3-V or 5-V logic signal which is not capable of effectively turning on a power switch. A level-shifting circuitry is required to boost the logic-level signal to the gate-drive voltage to fully turn on the power device and minimize conduction losses. Traditional buffer drive circuits based on bipolar or MOSFET transistors in totem-pole arrangement, being emitter follower configurations, prove inadequate for this because they lack level-shifting capability and low-drive voltage protection. Gate drivers effectively combine both the level-shifting and buffer drive functions. Gate drivers may also minimize the effect of switching noise by placing the high-current driver physically close to the power switch, drive gate-driver transformers and control floating power device gates, reducing power dissipation and thermal stress in controllers by absorbing gate-charge power losses.
In summary gate drivers are extremely important components in switching power combining benefits of high-performance, low-cost, low component count, board-space reduction, and simplified system design.