AN-6069
APPLICATION NOTE
Conclusion
Low-side drivers are used to drive power MOSFETs in
applications including clamped inductive load switching,
synchronous rectifier circuits, and pulse/gate transformer
drive circuits. The relationship of gate drive current to the
MOSFET switching and transition intervals has been
detailed during the prominent MOSFET switching intervals.
Potential driver solutions; including discrete components,
integrated PMOS/NMOS, and compound drivers, were
examined. Some of the non-ideal characteristics of the
various driver circuits were highlighted.
There is not a simple unified method to characterize the
output current sink and source capability of the many types
of drivers available. The test circuits presented in this note
can be used to investigate the VOUT vs. IOUT capability of
discrete and integrated circuit drivers, enabling evaluation
and comparison of drivers for a range of applications.
References
[1] 2006 Fairchild Power Seminar Topic, “Understanding Modern Power MOSFETs,” available on the fairchildsemi.com website at the link:
http://www.fairchildsemi.com/powerseminar/pdf/understanding_modern_power_mOSFETs.pdf
[2] Oh, K. S., “MOSFET Basics”, July, 2000, available as AN9010 from the fairchildsemi.com website.
[3] Balogh, L. “Design and Application Guide for High Speed MOSFET Gate Drive Circuits,” Power Supply Design Seminar SEM-1400, Topic 2,
Texas Instruments Literature No. SLUP169.
[4] ICE Components Gate Drive Transformer Datasheet “GT03.pdf” dated 10/06, available from www.icecomponents.com.
[5] 2006 Fairchild Power Seminar Topic, “Practical Power Application Issues for High Power Systems,” available on the fairchildsemi.com website at the
link: http://www.fairchildsemi.com/powerseminar/pdf/practical_power_high_power_systems.pdf
[6] Johnson, H. Dr, “High-Speed Digital Design On-Line Newsletter,” Vol. 3 Issue 8, www.sigcon.com/Pubs/news/3_8.htm
Author
Mark Dennis was born in Troy, NC, and received the Bachelor of Engineering degree from Duke University in 1983. After
graduation he has worked in industries encompassing power electronics applications such as offline and DC to DC power
supply design for telecom and computer systems, high voltage supplies for electrostatic precipitators, and online UPS
systems. For over eight years Mark has been working in the semiconductor industry and he is employed by Fairchild
Semiconductor as a Staff Engineer working in High Power Systems.
© 2007 Fairchild Semiconductor Corporation
Rev. 1.0.3 • 1/6/10
www.fairchildsemi.com
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