DC-DC
This application note will cover the layout and thermal design challenges. Finally, the
performances are demonstrated by two design examples: a 48 V-12 V 600 W 2-phase buck
converter and a 24 V to 5 V/3.3 V, 2 MHz dual output buck converter.
This application note shows how to design a 98% efficient 100–250 V to 40–60 V DC-DC
converter taking advantage of the low RDS(on) of EPC2215. A 3-level topology
offers a 2x reduction of voltage and current stresses, which improves overall
efficiency.
This application note discusses the design of a EPC9165, 2 kW, two-phase 48 V/12 V
bi-directional converter using GaN FETs in QFN packages, achieving 96% efficiency. The
heatsinking capability can be considered infinite since this will ultimately function
inside a vehicle with the unit mounted to the chassis.
To accommodate the increasing power requirement in the server applications, there is
increasing demand on extracting more power from standard 48 V bus converters. This
application note presents the design of a 1.2 kW, 4:1 conversion ratio, eGaN FET-based
LLC resonant converter in the 1/8th power brick size for the 48 V server applications.
The EPC9174 [1] converter module achieves 97.3% peak efficiency and 96.3% full-load
efficiency.
The 48 V/12 V automotive evaluation power modules (EPC9137, EPC9163, EPC9165, etc)
utilize the two-phase synchronous buck/boost topology. The edge connectors and
controller card are also designed to operate two modules in parallel with one
controller, effectively achieving four-phase and therefore double the rated current and
power
48 V is being adopted in many applications including AI systems, data centers, and mild
hybrid electric vehicles. However, the conventional 12 V ecosystem is still dominant and
so the need of a high power density 12 V to 48 V boost converter is required.
Modern displays typically require a low power boost converter. In this application, the
screen intensity is low to moderate and the converter operates at light load most of the
time, so the light load efficiency is very important.
This application note presents the design of a 1 kW, 4:1 conversion ratio, eGaN FET-based
LLC resonant converter in the 1/8th power brick size for the 48 V server applications.
The EPC9149 [5] converter module achieves 97.5% peak efficiency and 96.7% full-load
efficiency.
This application note discusses the design of a 1.5 kW, two-phase 48 V/12 V
bi-directional converter using automotive qualified GaN FETs that operates with 95%
efficiency. The heatsinking capability can be considered infinite since this will
ultimately function inside a vehicle with the unit mounted to the chassis. The design of
this converter is scalable to 3 kW by paralleling two converters.
Brick DC-DC converters are widely used in data center, telecommunication and automotive
applications, converting a nominal 48 V bus to (or from) a nominal 12 V bus. Advances in
GaN integrated circuit (IC) technology have enabled the integration of the half bridge
and gate drivers, resulting in a single chip solution that simplifies layout, minimizes
area, and reduces cost.
As computers, displays, smart phones and other consumer electronics systems become
thinner and more powerful, addressing the challenge of thinning the power converter and
getting more power out of limited space without increasing the surface temperature
increases in demand. This application note will look into designing a 44 V to 60 V
input, 12 V to 20 V, 12.5 A output, thin DC/DC power module with low temperature rise
using eGaN FETs in the simple and low-cost synchronous buck topology.
Brick DC-DC converters are widely used in data center, telecommunication and automotive
applications, converting a nominal 48 V to a nominal 12 V distribution bus among other
output voltages. The main trend has been towards higher power density given the form
factor is fixed. This application note discusses the design of a digitally controlled
1/16th brick converter using GaN FETs for a 48 V to 12 V, 9 V, 5 V application, with up
to 25 A output current, 300 W output power, a peak efficiency of 95.8%, and maximum
power density of 730 W/in3.
Over the past decade, DC-to-DC power modules in datacom, telecom, and consumer
electronics systems demand more power with increasing limitations on space and volume,
requiring ultra-thin and highly efficient solutions. The multi-level converter is an
exceptional candidate to shrink the size of the magnetic components and achieve high
efficiency in a compact solution.
The rapid expansion of the computing and telecommunication market is demanding an ever
more compact, efficient and high power density solution for intermediate bus converters.
The LLC resonant converter is a remarkable candidate to provide a high power density and
high efficiency solution. eGaN FETs with their ultra-low on-resistance and parasitic
capacitances, benefit LLC resonant converters by significant loss reduction that is
challenging when using Si MOSFETs.
The rapid expansion of the computing and telecommunication market is demanding an ever
more compact, efficient and high power density solution for intermediate bus converters.
The LLC resonant converter is a remarkable candidate to provide a high power density and
high efficiency solution. eGaN FETs with their ultra-low on-resistance and parasitic
capacitances, benefit LLC resonant converters by significant loss reduction that is
challenging when using Si MOSFETs.
Single-phase buck converter can work efficiently at output currents up to 25 A, but the
power efficiency drops significantly at higher currents. A compact, cost effective,
high-power and high-efficiency 48 V to 12 V buck converter, suitable for high-power
computing and telecommunication applications, can be achieved by employing eGaN FETs
such as EPC2045 in a multiphase topology.
The smallest, most cost effective, highest efficiency and 25 A capable non-isolated 48 V
to 5-12V converter, suitable for high-performance computing and telecommunication
applications, can be accomplished by employing eGaN® FETs such as the EPC2053. The
EPC9093 GaN development board configured as a synchronous buck converter yields a main
power stage area of only 10 mm x 9 mm, at least 2x smaller than its Si equivalent, and
is capable of producing an output voltage ranging from 5 V to 12 V.
The smallest, most cost effective and highest efficiency non-isolated 48 V to 12 V
converter, suitable for high-performance computing and telecommunication applications,
can be achieved by employing eGaN® FETs such as the EPC2045. The EPC9205
configured as a synchronous Buck converter yielded a power density of 1400
W/in3 and is capable of delivering 15 A.
The smallest, most cost effective and highest efficiency non-isolated 12 V to 1.0 V POL
converter, suitable for high-performance computing, cryptocurrency and telecommunication
applications, can be achieved by employing monolithic eGaN® IC half-bridges such as the
EPC2111. The EPC9204 configured as a synchronous Buck converter yielded a power density
of 1000 W/in3 and is capable of delivering 12 A.
Motor Drive
Due to the ever-increasing demand for highly efficient and compact motor drive
applications, EPC has designed the EPC9176 boards eGaN IC-based to provide a reference
design to achieve maximum performance for vacuum cleaner inverters.
Due to the ever-increasing demand for highly efficient and compact motor drive
applications, EPC has designed the EPC9173 board eGaN IC-based to provide a reference
design to achieve maximum performance for the eBike inverters. The EPC9173 is based on
six EPC23101 eGaN ICs. Such a board is a three-phase inverter capable of up to 1.5 kW
operation; when powered with a 48 VDC supply voltage, it can deliver 20 ARMS per phase
without a heatsink and with a heatsink it can provide continuously 25 ARMS per phase
with peak operation up to 35 ARMS (for time intervals smaller than 30 seconds).
Due to the ever-increasing demand for highly efficient and compact motor drive
applications, EPC has designed the EPC9167 and EPC9167HC boards eGaN FET-based to
provide a reference design to achieve maximum performance for the e-bike inverters.
Due to the ever-increasing demand for highly efficient and compact motor drive
applications, EPC has designed the EPC9145 board eGaN FET-based to provide a reference
design to achieve maximum performance in the field of motor drive inverters.
Brushless DC (BLDC) motors are popular and finding increasing application in robotics,
e-mobility, and drones. Such applications have special requirements such as lightweight,
small size, low torque ripple, and precision control. To address these needs, inverters
powering the motors need to operate at higher frequency, but require advanced techniques
to reduce the resultant higher power loss.
AC/DC
EPC recently introduced the EPC9171[1], a GaN FET based USB power supply meeting the USB
PD3.1 standard. With a universal input and 48 V output it can deliver up to 240 W and
achieve 92% peak efficiency under both 120 VACRMS and 230 VACRMS
input and 72 °C temperature rise (around the rectifier FETs).
The expansion of applications such as cloud computing, wearables, machine learning,
autonomous driving, and IoT drive us towards an even more data-intensive world,
increasing demands on data centers and power consumption [1, 2]. The importance of
efficiency, power density, and cost of the AC to DC switching power supply is driving
innovative solutions that eGaN FETs can solve to yield ultra-high efficiency power
factor correction (PFC) front-end rectifier solutions that are the focus of this
how-to-application note.
Design
eGaN FET-based power conversion systems offer higher efficiency, increased power density,
and lower overall system cost than Si-based alternatives. These advantageous
characteristics have spurred the presence of an ever increasing ecosystem of power
electronics components such as gate drivers, controllers, and passive components that
specifically enhance eGaN FET performance.
eGaN FETs are capable of switching much faster than Si MOSFETs, requiring more careful
consideration of PCB layout design to minimize parasitic inductances. Parasitic
inductances cause higher overshoot voltages and slower switching transitions. This
application note reviews the key steps to design an optimal power stage layout with eGaN
FETs, to avoid these unwanted effects and maximize the converter performance.
EPC’s wafer level chip-scale packaging such as the Land Grid Array (LGA) and Ball Grid
Array (BGA) packages shown in figure 1, has enabled a new level of performance in power
conversion. Many of these parts use a fine pitch down to 400 μm which means a proper PCB
footprint design is essential for consistent and reliable assembly of the GaN device.
Here are the guidelines of designing a correct footprint for any EPC part working from
the datasheet.
EPC’s innovative wafer level, Land Grid Array (LGA) and Ball Grid Array (BGA) packaging
has enabled a new level of performance in power conversion. Proper assembly techniques
are essential to take full advantage of GaN technology capability. Here are the
guidelines for manual assembly of these FETs and ICs.
eGaN FETs and ICs enable very high-density power converter design, owing to their compact
size, ultra-fast switching, and low on-resistance. The limiting factor for output power
in most high-density converters is junction temperature, which prompts the need for more
effective thermal design. The chip-scale packaging of eGaN also offers six-sided
cooling, with effective heat extraction from the bottom, top, and sides of the die. This
application note presents a high-performance thermal solution to extend the output
current capability of eGaN-based converters.
Advancements in eGaN FET-based converters’ in-circuit capability drives high performance
measurement requirements. This article compares various measurement techniques and
technologies’ capability of accurately evaluating high performance eGaN FETs in
applications.