GaN Talk Blog

There is increasing demand for extracting more power from standard 48 V bus converters for server applications' ever-increasing power requirements. GaN power devices allow a designer to achieve a converter's goals: high efficiency, small size & high current handling, ease, and high reliability. To whet your appetite, EPC designed a 1.2 kW resonant converter demo board (EPC9174) in an 1/8^th brick form factor that achieves an impressive 97.3% peak efficiency.

When “displacement” technologies such as EPC’s GaN power FETs and ICs are introduced and new levels of performance are possible, modeling your design offers comfort and insight to your circuits’ capabilities and needs. This blog post discussed the latest addition to the “EPC GaN Power Bench, our on-line modeling tool library, EPC’s GaN FET Thermal Calculator! 

APEC is The Premier Global Event in Applied Power Electronics

Preparations are well underway for EPC to head to Houston for the Applied Power Electronics Conference (APEC). The team is excited to be back, in-person exhibiting a large variety of demonstrations showcasing how the superior performance of GaN is transforming the delivery of power across many industries, including computing, communications, and e-mobility.

Here’s a sneak peek at some of the key application areas we will be showcasing in Booth 1302 at APEC.

Mobility is a driving factor in all economies. Electro mobility (or e-Mobility) is a clean and impactful way of keeping the gears of commerce grinding without contributing to the environmental stresses of inefficient motors or fossil fuel burning engines that cause damage to our planet. There is an ever-increasing demand for highly efficient and compact motor drive designs. EPC’s GaN-based motor drive reference designs for eMobility applications are in development to jump-start the competitive and environmentally friendly alternatives that support this trend.

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. An example using EPC9137 modules are shown in Figure 1.

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, so a high power density 12 V to 48 V boost converter is required. The fast-switching speed and low R_DS(on) of eGaN FETs can help address this challenge. In this post, the design of a 12 V to 48 V, 500 W DC-DC power module using eGaN^® FETs directly driven by eGaN FET compatible ISL81807 controller IC from Renesas in the simple and low-cost synchronous boost topology is evaluated.

Modern displays, such as laptops and PC monitors, typically require a low power boost converter. In this application, the screen intensity is low to moderate and the converter is operated at light load most of the time, so the light-load efficiency is very important. The low switching loss of eGaN FETs can help address this challenge. This GaN Talk will examine the design of a 12 V to 60 V, 50 W DC/DC power module with low temperature rise using eGaN FETs in the simple and low-cost synchronous boost topology.

This GaN Talk blog discusses the advantages of using GaN-based inverters instead of silicon-based inverters for motor drive designs to operate smoother while reducing size and weight. These advantages are critical for motor drives used in typical applications such as warehousing & logistical robots, servo drives, e-bikes & e-scooters,  collaborative and low voltage robots and medical robotics, industrial drones, and automotive motors.

Omdia forecasts that worldwide shipments of warehousing and logistics robots will grow rapidly over the next 5 years from 194,000 units in 2018 to 938,000 units annually by 2022, with the rate of growth slowing after 2021 as many major players will have adopted robotic systems by then.  Worldwide revenue for this category will increase from $8.3 billion in 2018 to $30.8 billion in 2022, providing significant opportunities for established participants and emerging players.

EPC development boards offer the opportunity to evaluate eGaN^® FETs and ICs in common applications. For example, the EPC9094 half-bridge development board can be configured as a buck or boost converter. The EPC9094 features the newly released EPC2054 200 V 43 mOhm max eGaN FET in a 1.3 x 1.3 mm 2 x 2 pin WLCSP package. The very low R_DS(on) value of this very small FET permits it to support high current loads from a high voltage supply. To demonstrate this ability, we will modify the EPC9094 development board to a buck converter. Using a 140 V supply, Spice simulation suggest 28 V output at 2.5 A will offer a high 90% efficiency. A Vishay IHLP-4040DZET330M11, 33 uH, 4.4 A, 95 mOhm Max, 10.2 x 10.8 x 4 mm inductor is selected which will provide 40% ripple at 500 Khz. Output capacitors consisted of four 10 uF Y5V 50V 1210 ceramic capacitors. The simulation showed a tradeoff between ripple current and overall efficiency when switching frequency was changed between 500 kHz down to 375 kHz. The simulation also showed that adjusting the dead time to permit full ZVS transition from high to low maximized the light load efficiency performance in the buck converter.

Until recently, to achieve high-quality sound from an audio amplifier cost thousands of dollars and relied on a large, heavy, power-hungry class-A amplifier. Now, the advent of gallium nitride FETs and ICs is ushering the age of high quality, lower cost class-D audio amplifiers. 

Distortion Performance Issues Lowered with GaN

Historically, meeting the required distortion performance targets (THD+N, TIM and IM) for high-quality audio, class-D amplifiers had to resort to incorporating large amounts of feedback circuitry to compensate for poor open-loop performance. The source of this distortion was the silicon power MOSFET.