IEEE Power Electronics Magazine - September 2019 - 38

feature on-board gate drives and include all the critical components and layout for optimal switching performance.
These design resources demonstrate Transphorm's GaN
technology and performance," said Philip Zuk, Transphorm's vice president of technical marketing worldwide.
According to Silicon Labs, its ISODrivers facilitate
safety by integrating safety functions, such as dead-time
programmability, overlap protection, power status pin on
the control side, and asynchronous shutdown protection,
CMOS-based capacitive isolation technology, low electromagnetic emissions, high immunity to external fields
(>200 kV/µs), and robust industrial grade performance. It
offers high-side/low-side drivers or dual drivers in compact
LGA/QFN packages or wide creepage (>8 mm) SOIC with
AEC-Q100 qualification.
Another discrete GaN FET supplier recommending Silicon Labs' gate drivers is GaN Systems. According to Peter
Di Maso, director of product line management, "GaN Systems' enhancement mode HEMTs are easily driven with a
positive voltage from gate to source to turn them on and
applying 0 V gate-to-source to turn off the devices. This
is very much like a MOSFET. The main difference is the
threshold and maximum gate voltages. The typical transistor threshold voltage is ~1.7 V with full enhancement
at ~6.0 V. The maximum drive voltage is 7 V, but the gate
can handle a transient voltage of 10 V. Negative gate voltage, from −2 to −3 V, can be used to improve turn-off performance but is not necessary. The gate pins can withstand
up to −20-V transients. The gate capacitance, charge, and
leakage current characteristics of the transistors are much
lower than existing transistor technologies. This means
that the drive current requirements can easily be met with
MOSFET drivers. There are some applications that do not
require any drivers using GaN Systems' transistors. This
is made possible with the implementation of our EZDrive
circuit and standard PWM controllers." Gate drive design
considerations with recommended drivers, which includes
Analog Devices, TI, pSEMI, and uPI Semiconductor gate
drive reference designs, are provided in [5].
In half-bridge designs, the drivers are similar, but more
attention is needed for driving high-side GaN transistor,
noted Di Maso. He added, "The high-side transistor has the
same drive requirements as the low-side transistor with the
added requirement of getting the high-side drive signal (voltage and currents) from a low-side reference point. This can
be achieved in several ways. The first and simplest is using
a bootstrap circuit and nonisolated level-shifted driver.
This type of circuit is popular in lower bus voltage (<100 V)
applications. As the bus voltage and power level increase,
more stringent requirements are needed, like isolation for
gate signal driving and isolated power rails for supplying
drive current to the high side transistor and high CMTI."
Infineon's EiceDriver is optimized to drive the company's CoolGaN HEMTs and Panasonic GaN switches. "This
driver is based on an RC gate drive that provides both a lowimpedance charging path for fast switching transients and

IEEE POWER ELECTRONICS MAGAZINE

z September 2019

a negative gate drive," said Vincent Chi Zhang, staff engineer, Application Engineering for gate driver ICs at Infineon. He added, "In contrast to the classic RC concept, the
new driver is able to provide a negative gate drive without
the need for a negative supply voltage for the first switching
pulse after an extended nonswitching period (e.g., during
burst mode operation or startup). In these situations, the
high-voltage/current stress on the GaN switch due to shootthrough effects can be avoided." Furthermore, he continued, "the GaN driver can be switched from negative gate
drive to zero to avoid increased losses in reverse operation."
Additionally, this EiceDriver is galvanically isolated
and is being used in PFC totem-pole designs, telecom rectifiers, and server switch-mode power supplies. "This leads
to improvements in higher efficiency, higher working frequency, and higher power density, stated Zhang. Going
forward, according to Zhang, Infineon plans to add more
functions to the EiceDriver package and further reduce
the external component count to cut power supply size and
increase ease of use.

About the Author
Ashok Bindra (bindra1@verizon.net) obtained his M.S.
degree from the Department of Electrical and Computer
Engineering, Clarkson College of Technology (now Clarkson University), Potsdam, New York and M.Sc. degree in
physics from the University of Bombay, India. He is the
editor-in-chief of IEEE Power Electronics Magazine and a
Member of the IEEE. He is a veteran freelance writer and
editor with more than 35 years of editorial experience covering power electronics, analog/radio-frequency technologies, and semiconductors. He has worked for leading electronics trade publications in the United States, including
Electronics, EE Times, Electronic Design, Power Electronics Technology, and RF Design.

References
[1] N. Sridhar. (2019). Silicon carbide gate drivers-a disruptive technology
in power electronics. Texas Instruments. Dallas. [Online]. Available: http://
www.ti.com/lit/wp/slyy139a/slyy139a.pdf
[2] Infineon Technologies, "Advanced gate drive options for silicon-carbide
(SiC) MOSFETs using EiceDRIVER," Infineon Technologies, Munich, Rep.
AN2017-04, 2018. [Online]. Available: https://www.infineon.com/dgdl/Infineon
-Silicon-Carbide_(SiC)_MOSFETs_using_EiceDRIVER(TM)_Advanced
_Gate_Drive_Options-ApplicationNotes-v01_01-EN.pdf?fileId=5546d4625b3c
a4ec015b47c9ac35705b
[3] Y. Xie and P. Brohlin. (2016). Optimizing GaN performance with an integrated driver. Texas Instruments. Dallas. [Online]. Available: http://www
.ti.com/lit/wp/slyy085/slyy085.pdf
[4] Nick Fichtenbaum, "GaN Power Integrated Circuit," presented at the 77th
Device Research Conf., University of Michigan, Ann Arbor, June 23-26, 2019.
[5] GN001 Application Guide, "Design with GaN Enhancement mode HEMT,"
GaN Systems Inc., Ottawa, Ontario, Canada, Apr. 12, 2018. [Online]. Available: https://gansystems.com/wp-content/uploads/2018/04/GN001-Design
_with_GaN_EHEMT_180412.pdf

http://www.ti.com/lit/wp/slyy139a/slyy139a.pdf http://www.ti.com/lit/wp/slyy139a/slyy139a.pdf https://www.infineon.com/dgdl/Infineon-Silicon-Carbide_(SiC)_MOSFETs_using_EiceDRIVER(TM)_Advanced_Gate_Drive_Options-ApplicationNotes-v01_01-EN.pdf?fileId=5546d4625b3ca4ec015b47c9ac35705b https://www.infineon.com/dgdl/Infineon-Silicon-Carbide_(SiC)_MOSFETs_using_EiceDRIVER(TM)_Advanced_Gate_Drive_Options-ApplicationNotes-v01_01-EN.pdf?fileId=5546d4625b3ca4ec015b47c9ac35705b https://www.infineon.com/dgdl/Infineon-Silicon-Carbide_(SiC)_MOSFETs_using_EiceDRIVER(TM)_Advanced_Gate_Drive_Options-ApplicationNotes-v01_01-EN.pdf?fileId=5546d4625b3ca4ec015b47c9ac35705b https://www.infineon.com/dgdl/Infineon-Silicon-Carbide_(SiC)_MOSFETs_using_EiceDRIVER(TM)_Advanced_Gate_Drive_Options-ApplicationNotes-v01_01-EN.pdf?fileId=5546d4625b3ca4ec015b47c9ac35705b http://www.ti.com/lit/wp/slyy085/slyy085.pdf http://www.ti.com/lit/wp/slyy085/slyy085.pdf https://www.gansystems.com/wp-content/uploads/2018/04/GN001-Design_with_GaN_EHEMT_180412.pdf https://www.gansystems.com/wp-content/uploads/2018/04/GN001-Design_with_GaN_EHEMT_180412.pdf

IEEE Power Electronics Magazine - September 2019

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