Datasheet
5
10
15
20
0 4 8 12 16 20
Supply Voltage (V)
Rise Time (ns)
G008
2
4
6
8
10
0 4 8 12 16 20
Supply Voltage (V)
Fall Time (ns)
G009
UCC27511
UCC27512
www.ti.com
SLUSAW9E –FEBRUARY 2012–REVISED DECEMBER 2013
TYPICAL CHARACTERISTICS (continued)
RISE TIME FALL TIME
vs vs
SUPPLY VOLTAGE SUPPLY VOLTAGE
Figure 17. Figure 18.
APPLICATION INFORMATION
Introduction
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
employs between the PWM output of controllers and the gates of the power-semiconductor devices. Further,
gate drivers are indispensable when having the PWM controller directly drive the gates of the switching devices
is impossible. With advent of digital power, this situation will be often encountered since 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. Traditional buffer drive circuits based on NPN/PNP bipolar
transistors in totem-pole arrangement, being emitter follower configurations, prove inadequate with digital power
since they lack level-shifting capability. 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 band-gap 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 VDD 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 and simplified system design.
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