Page 23 - EE Times Europe Magazine | June2020

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GaN HEMTs Outperform MOSFETs in Key Growth Applications

An increase in performance to 30 V enables
GaN to be used to build high-power DC/DC
converters, point-of-load (PoL) converters,
and synchronous rectifiers for isolated power
supplies, PCs, and servers.
The smallest, most cost-effective, and
highest-efficiency non-isolated 48-V to 12-V
converter, suitable for high-performance
computing and telecommunication applica-
tions, can be achieved by employing eGaN
FETs such as the EPC2045, according to EPC.
The EPC2045 has an operating temperature
of –40°C to 150°C with thermal resistance
of 1.4°C/W. The drain-source on-resistance
(R DS(on) ) is 5.6 mΩ typical (Figures 3 and 4). Figure 5: EPC9148 GaN transistor board
In the consumer market, portable solutions for consumer applications (Image: EPC)
are becoming increasingly energy-hungry.
Figure 3: Representation of a 48-V mild Efficiency and thermal management are crit-
hybrid system ical in small platforms with minimal cooling
solutions. The need for fast and efficient
For 48-V bus systems, GaN technology chargers has led the consumer market toward
increases efficiency, reduces system size, and GaN solutions (Figure 5).
reduces system cost. A 250-kHz GaN solution
with double the frequency allows a 35% LiDAR
reduction in size, lowering inductor DC resis- The eGaN FETs and integrated circuits are
tance (DCR) losses as well as cutting system the logical choices to use when turning on a
cost by approximately 20% compared with laser in a LiDAR system because FETs can be
the MOSFET solution. GaN’s exceptionally activated to create high-current pulses with
high electron mobility and low temperature extremely short pulse widths. “The short
coefficient allow low Q G and zero reverse- pulse width leads to higher resolution, and
recovery charge (Q RR) ). The final result is a the higher pulse current allows LiDAR sys- Figure 6: EPC9144 development board
device that can manage tasks with a very tems to see further,” said Lidow. “These two (Image: EPC)
high switching frequency for which a low on features, together with their extremely small
time is beneficial, as well as those in which size, make GaN ideal for LiDAR.”
on-state losses dominate. EPC provides various development boards Cepton Technologies’ Helius LiDAR solu-
“High-power EPC eGaN FETs’ lower for its eGAN FETs. The EPC9144 is mainly tion, based on the EPC technology, delivers
resistance in the on state, lower capaci- designed to drive high-current laser diodes advanced object detection, tracking, and
tance, higher current, and excellent thermal with high-current pulses at a total pulse classification capabilities to enable applica-
performance characterize these power width of 1.2 ns and current up to 28 A tions for smart cities, transport infrastructure,
converters with over 98% efficiency,” said (Figure 6). The board is designed around the security, and more. It combines industry-
Alex Lidow, CEO and co-founder at EPC. “This 15-V EPC2216 eGaN FET, which is automo- leading 3D LiDAR sensing powered by
family of eGaN FETs halves the drain-source tive-qualified to AEC-Q101. The EPC9126 and Cepton’s patented Micro Motion Technology
on-resistance to enable high-current and EPC9126HC development boards are primarily (MMT), edge computing for minimum data
high-power-density applications.” intended to drive laser diodes with high- burden and maximum ease of integration,
The latest generation of eGaN FETs also current pulses and total pulse widths as low and built-in advanced perception software for
halves the hard-switching figure of merit as 5 ns (10% of peak). They are designed with real-time analytics.
compared with the previous generation for the 100-V EPC2212 and EPC2001C enhance- “LiDAR has become a very significant
improved switching performance in high- ment-mode eGaN FETs, capable of 75-A and market,” said Lidow. “It is probably most
frequency power conversion applications. 150-A current pulses, respectively. recognized as the solution for autonomous
cars. However, a faster-growing market is
for short-range LiDAR, which is being used
for things like robots that only need to see a
few feet, drones for collision avoidance, and
driver-alertness systems.
“Short-range LiDAR systems do not
require as much current as long-range LiDAR
systems. But seeing [over a] short distance
means you need an even faster pulse, because
if you’re measuring something that is 1 meter
away, [for example], the return signal will
come back in just nanoseconds. We’ve demon-
strated systems for short-range LiDAR that
have pulse widths less than 1.2 ns.”
Figure 4: Efficiency versus current (Image: EPC)

www.eetimes.eu | JUNE 2020