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Power Supply Power Supply
In addition to the time of flight example, the in- er precision in the positioning of the motor. The and op amps to construct an integrated control- that work on the first pass. The lack of a library
tegrated power stage has been tested in a three- positioning of motors is critical for many robotic ler plus output stage on a single chip. Multi-level of circuit blocks makes the design phase longer
phase motor drive application, pictured in figure implementations. topologies can also be integrated, thus enabling than it would be with pure predesigned circuit
8. The advantage in this application is the ability higher input voltages with lower voltage power blocks because the design process requires
to go to a much higher switching frequency for devices. more iterations, and a higher skill level for the IC
the motor drive, which reduces size (this solu- THE FUTURE OF GAN designer. Third, discrete technology continues to
tion is only 45 mm by 55 mm), reduces weight, Figure 9 shows a summary of the ongoing eGaN In a few years, the merging of discrete technol- develop rapidly, GaN is still 300 times away from
reduces audible noise, and provides much high- technology journey. EPC is in generation ”five ogy to integrated circuits will occur. As discrete its theoretical performance limit.
plus” of its discrete platform, illustrated in the devices achieve increasingly higher power den-
top bar of figure 9. With regard to integrated cir- sities, it will no longer be possible to extract the If the growth of the IC platform cannot rapid-
cuits, what started with monolithic half bridges current in and out of the bumps and bars on the ly follow the discrete platform, the ICs will not
has subsequently expanded to add more func- devices. Therefore, integration into small, mul- yield the performance advantages that can still
tions and features as illustrated in the bottom ti-chip, multi-function integrated circuits will be be achieved from discrete transistors. So, what
bar of figure 9. necessary. It is likely that within the next three is required to overcome these challenges is the
to four years the slow obsolescence of discrete extremely rapid development of process design
The monolithic power stage IC discussed in the transistors in power conversion will occur and kits that automate the design function of the IC,
previous section performs all the same basic integrated solutions will be the component that and iterations of design kits that keep pace with
functions as a multi-chip DrMOS module based designers select when building a power system. the rapid pace of technology development.
on silicon MOSFETs, but at higher voltages, higher
switching speed, in a smaller footprint, and at
lower cost. These first-generation power stag- THE CHALLENGES TO SUMMARY
es only include capacitors, resistors and lateral INTEGRATION EPC’s eGaN technology is developing rapidly
n-channel FETs. Soon additional sensing of cur- There are some challenges remaining before with increasing releases of new generations of
Figure 8: photo of 500 W, three-phase motor drive circuit rent and temperature can be included along with complete system-on-chip solutions in GaN can discrete devices, which become the platform
using the EPC2152, ePower™ Stage (circled).
circuit blocks such as references, comparators, be achieved. First, there are no p-channel devic- for new generations of more efficient, smaller,
es in gallium nitride yet, and that makes circuit and lower cost integrated circuits. GaN integrat-
design far more difficult. In particular, it is not ed circuits make products smaller, faster, more
possible to make good CMOS circuits. Second, efficient, and easier to design. The ascent of GaN
there are fewer predesigned circuit blocks. is redefining power conversion, and integrated
circuits have the biggest impact from this great
GaN is a relatively new technology and so there new technology!
is not a huge library of circuit blocks that can be
For More Information
▶ EPC
▶ (PM1) Keynote: Redefining Power Conversion with GaN Integrated Circuits, Alex
Lidow – Talk at Power Forum
Figure 9: Roadmap for GaN technology discrete and integration development.
34 MARCH 2021 | www.powerelectronicsnews.com MARCH 2021 | www.powerelectronicsnews.com 35
simply “cut and pasted” to make large systems
