APEC roundup: WBG and industrial power spotlighted

The technical sessions at the Applied Power Electronics Conference & Exposition (APEC 2021) mirrored key power trends across industries: the demand for higher efficiency, improved thermal management, and miniaturization. These requirements are seen across industries — automotive, industrial, mobile devices, data centers, and renewable energy.

To meet these challenges, power designers are turning to wide-bandgap (WBG) semiconductors, which were highlighted by a number of WBG devices featured at the show. WBG devices, both silicon carbide (SiC) and gallium nitride (GaN), are a growing segment of the power device market. These devices offer inherent advantages over silicon, including higher bandgaps and lower conduction losses, finding homes in electric vehicles (EVs), telecom, and renewable energy.

At the same time, there is increasing demand for power devices that meet harsh industrial environments. Many of these devices are focused on improving overall efficiency and reducing board space.

Here is a selection of power devices featured at APEC 2021.

WBG devices

SiC technology is making big inroads in EVs thanks to several advantages over silicon, including better switching and improved thermal performance, translating into higher efficiency, higher power density, and smaller size. One of the newest SiC devices for EVs comes from ON Semiconductor. The company showcased several SiC solutions, including 650-V SiC MOSFETs and 1,200-V and 900-V N-channel SiC MOSFETs. The company also hosted several seminars about off-board EV charging.

Two of ON Semiconductor’s latest SiC products aimed at EVs are 1,200-V SiC MOSFET two-pack modules. These modules, based on planar technology, can drive a voltage range of 18–20 V. The devices are simple to drive with negative gate voltages, said the company.

Designed for EV charging station applications and configured as a two-pack half bridge, the NXH010P120MNF1 is a 10-mΩ device housed in an F1 package, while the NXH006P120MNF2 is a 6-mΩ device in an F2 package. The packages feature press-fit pins, making them also suitable for industrial applications.

The SiC MOSFET modules also feature an embedded negative temperature coefficient (NTC) thermistor for temperature monitoring. In addition to EV charging, these devices can be used in solar inverters, uninterruptible power supplies, and energy storage systems.

While SiC technology is making headway in EV markets, many of the WBG devices featured at APEC are based on GaN technology. GaN devices offer several benefits over silicon, including a smaller size, higher thermal conductivity, and high efficiency. Here are a few examples from Efficient Power Conversion (EPC), GaN Systems, Nexperia, Power Integrations, and Texas Instruments.

EPC showcased its latest enhancement-mode GaN-based field-effect transistors (eGaN FETs) and ICs for high-power–density computing, automotive, e-mobility, and robotics. The company also hosted several technical sessions featuring its eGaN FETs and ICs.

New products include 48-V bus power distribution products such as the EPC9137, a 1.5-kW two-phase 48- to 12-V bidirectional converter that operates with 97% efficiency in a very small footprint. The EPC9137 DC/DC converter is said to be 3× faster and over 35% smaller and lighter with greater than 1.5% higher efficiency compared with silicon MOSFET solutions.

EPC also offers a scalable demo board that allows two converters to be paralleled to achieve 3 kW or three converters paralleled to achieve 4.5 kW. The board features four EPC2206 100-V eGaN FETs and is controlled by a module that includes the Microchip dsPIC33CK256MP503 16-bit digital controller.

EPC eGaN FETs can operate with 97% efficiency at 250-kHz switching frequency, enabling 800 W/phase compared with silicon-based solutions, said EPC. In addition, it is possible to reduce the number of phases from five to four for a 3.5-kW converter while increasing efficiency, added the company.

The company also announced the expansion of its 80-V and 200-V eGaN FET portfolio. This includes the EPC2065 and EPC2054 eGaN FETs.

GaN Systems demoed its most recent GaN-based solutions for a range of applications, from mobile phone and laptop PC chargers to EVs. One solution is a reference design for a high-density, high-efficiency GaN-based 3-kW LLC resonant converter (GS-EVB-LLC-3KW-GS), targeting data center, telecom, and industrial switch-mode power supply (SMPS) applications. The full-bridge LLC resonant converter design, integrating the company’s 650-V e-mode transistors, exceeds the 80 PLUS Titanium standard for power supply units, achieving high power density (AC/DC PSU) above 100 W/in.³ and high efficiency of more than 96%.

GaN Systems also demoed several consumer charger products, including the 100-W dual USB-C intelligent PD GaN charger and examples of high-efficiency GaN-based 65-W QR and 65-W active clamp flyback (ACF) chargers. For automotive, the company highlighted its automotive-grade 650-V, 60-A transistors, which meet the requirements for high power, low loss, and high reliability.

Nexperia highlighted its power GaN FET family, focusing on the 650-V devices, along with its CCPAK surface-mount packaging. A few of the latest new products include its second-generation 650-V power GaN FET device family, targeting server and telecom power supplies.

The 650-V GaN FETs meet 80 PLUS Titanium–class power supplies (single-phase AC/DC and DC/DC industrial SMPS) operating at 2 kW to 10 kW, with an R_DS(on) down to 35 mΩ (typical). They also can be used in solar inverters and servo drives in the same power range.

The 650-V H2 power GaN FETs, housed in TO-247 packaging, deliver a 36% shrinkage in die size for a given R_DS(on) value for better stability and efficiency, said the company. In addition, the cascode configuration eliminates the need for complicated drivers, speeding time to market.

Nexperia offers a range of GaN FET devices that feature its next-generation high-voltage GaN HEMT H2 technology, targeting automotive, 5G, and data center applications. The devices are housed in standard TO-247 and the company’s proprietary CCPAK surface-mount packaging with a copper clip.

Power Integrations focused its APEC sessions on BLDC motor driver solutions, design automation tools, and PowiGaN devices. One of the newest in the PowiGaN device family is the InnoSwitch4-CZ flyback switcher ICs with GaN technology, targeting a new class of ultra-compact mobile charging devices.

The InnoSwitch4-CZ family of high-frequency, zero-voltage–switching flyback switcher ICs incorporates a 750-V primary switch using the company’s PowiGaN technology and a novel high-frequency ACF controller to enable a new class of ultra-compact and ultra-efficient chargers for phones, tablets, and laptops.

The InnoSwitch4-CZ and ClampZero active clamp combo provides up to 95% efficiency and maintains very high efficiency across variations in line voltage, system load, and output voltage in comparison with older ACF approaches, said Power Integrations.

Along with several technical sessions, among the featured products that Texas Instruments Inc. highlighted at APEC are its GaN FETs. Last November, TI claimed the first automotive GaN FETs with integrated driver, protection, and active power management for automotive and industrial applications. Expanding its high-voltage GaN FET power management portfolio, the new 650-V and 600-V GaN FETs deliver twice the power density and achieve 99% efficiency compared with existing solutions, said TI.

In addition, when combined with the advanced control features in the C2000 real-time microcontrollers, such as the TMS320F2838x or the TMS320F28004x, the LMG3522R030-Q1 GaN FET enables switching frequencies greater than 1 MHz in power converters, reducing magnetics size by 59% versus existing silicon and SiC solutions, said TI.

With a fast-switching, 2.2-MHz integrated gate driver, the GaN FETs also integrate internal protection and temperature sensing, which helps reduce board space in power management designs. This integration, together with the high power density of TI’s proprietary GaN technology, enables engineers to eliminate more than 10 components typically required for discrete solutions, said TI. In addition, each of the new 30-mΩ FETs can support up to 4 kW of power conversion when applied in a half-bridge configuration.

TI said the automotive GaN FETs can help reduce the size of EV on-board chargers and DC/DC converters by as much as 50% compared with existing silicon or SiC solutions, offering EVs an extended battery range, increased system reliability, and lower cost.

For industrial applications, the new devices enable high efficiency and power density in AC/DC power-delivery applications in which low losses and reduced board space are important, said TI. Applications include hyperscale and enterprise computing platforms as well as 5G telecom rectifiers.

Industrial power

Infineon Technologies AG featured a host of power management solutions at APEC this year, ranging from silicon to WBG devices, covering a range of applications from computing and data center to renewable energy and e-mobility. The company also highlighted its industrial power and motor control product line.

One of the devices that Infineon featured is the latest addition to its EiceDRIVER product portfolio, the 6EDL7141 three-phase gate driver IC for advanced motor control in battery-powered consumer and industrial applications. Aimed at delivering higher power density and improved system efficiency, the programmable solution for advanced motor control applications is packaged in a 48-pin VQFN with a 7 × 7-mm² footprint. When combined with Infineon’s power MOSFETs, the devices offer a complete solution.

Key features of the EiceDRIVER 6EDL7141 include an SPI interface for gate drive output configuration, an integrated power supply, and dual charge pumps to supply all system functions. Thanks to an operating voltage range from 5.5 to 60 V and a configurable driving current up to 1.5 A, the device can drive a wide range of MOSFETs. It also offers an adjustable gate driver supply voltage setting between 7 V, 10 V, 12 V, and 15 V.

The integrated buck regulator requires only an external capacitor and inductor to provide power for both the microcontroller and the Hall sensors in the motor, said Infineon, which reduces board space and the number of external components required.

ON Semiconductor launched a couple of integrated power modules for industrial applications. The two new integrated, converter-inverter-power factor correction (PFC) modules are designed for industrial motor drives, servo drives, and HVAC, where they are used to drive motors for applications including fans and pumps.

The NXH50M65L4C2SG and NXH50M65L4C2ESG are transfer-molded power-integrated modules that target rugged industrial applications with high output power.

The NXH50M65L4C2SG and NXH50M65L4C2ESG, based on a standard aluminum oxide (Al₂O₃) substrate and an enhanced low-thermal–resistance substrate, respectively, contain a converter−inverter−PFC circuit consisting of a single-phase converter with four 75-A, 1,600-V rectifiers. The three-phase inverter (NXH50M65L4C2ESG) uses six 50-A, 600-V IGBTs with inverse diodes, and the dual-channel interleaved PFC (NXH50M65L4C2SG) integrates two 75-A, 650-V PFC IGBTs with inverse diodes and two 50-A, 650-V PFC diodes. An NTC thermistor is embedded to allow for monitoring of device temperature during operation.

Thanks to the pre-assembled and optimized module, parasitic elements are very small when compared with discrete PCB-based designs, said ON Semiconductor, allowing a wide PFC switching frequency range between 18 kHz and 65 kHz.

ON Semiconductor also claimed the industry’s first totem-pole PFC controller for ultra-high–density offline power supplies. The NCP1680 critical-conduction–mode totem-pole PFC controller uses a novel current-limit architecture and line-phase detection together with proven control algorithms.

By replacing rectifier bridge diodes with switches in a totem pole configuration and “pulling in the boost PFC function,” the NCP1680 can reduce bridge losses and improve overall efficiency, said the company. In addition, the NCP1680 can support any switch type, including superjunction silicon MOSFETs or WBG switches such as SiC or GaN devices.

The integrated device can be used in power supply designs for telecom 5G, industrial, and high-performance computing that operate with universal mains (90–265 VAC) at recommended power levels up to 350 W. As an example, with a 230-VAC mains input, PFC circuits based on the NCP1680 are capable of achieving close to 99% efficiency at 300 W.

TI also showcased an integrated DC/DC controller that reduces conducted emissions and power supply size in automotive, industrial, and communications applications. The company claims these are the first DC/DC controllers with an integrated active EMI filter (AEF) that help engineers design the smallest power supply solutions with low electromagnetic interference (EMI). In addition to the integrated AEF, the new family of synchronous DC/DC buck controllers — the LM25149-Q1 and LM25149 — incorporate dual-random spread-spectrum technology, which further helps mitigate EMI.

There are a couple of scenarios by which the new LM25149-Q1 and LM25149 DC/DC controllers help power designers. The devices can either cut the area of the external EMI filter in half and lower the conducted EMI of the power design by as much as 55 dBµV across multiple frequency bands or achieve a combination of reduced filter size and low EMI, according to TI.

The integrated AEF, by lessening the filtering burden on the passive elements, reduces the size, volume, and cost of the passive EMI filter, enabling engineers to achieve the smallest-possible low-EMI power design, said TI. The integrated AEF can reduce the size of the EMI filters by up to 50% in area and 75% in volume. The buck controllers also feature frequency synchronization to an external clock, which further reduces EMI.

Other features that help increase power density include interleaved dual-phase operation and the integration of the bootstrap diode, loop compensation, and output-voltage feedback components. TI noted that engineers have an option to use external feedback and loop compensation to further optimize their designs.

Trinamic Motion Control GmbH & Co. KG, now part of Maxim Integrated Products Inc., introduced ahead of APEC an end-of-arm tooling reference design for industrial robotics and the single-axis servo controller/driver with integrated motion control.

The open-source TMCM-1617-GRIP-REF reference design integrates hardware-based field-oriented control (FOC) and three communication ports, supporting industrial EtherCAT, IO-Link, or RS-485 communication. The reference design features Maxim Integrated’s industrial-grade MAX22000 high-precision configurable analog input/output and MAX14906 quad-channel digital input/output to adjust the multiple modes of the Trinamic TMCM-1617 single-axis servo driver.

Trinamic said the design shrinks the size of the robotic grippers by 3× while reducing development time in half, thanks to the fully integrated, intelligent hardware platform that provides motor control algorithms as well as protocol stacks. All of these features — hardware-based FOC, software-configurable inputs/outputs, and three communication protocol stacks — fit into a compact solution size that measures 4,197 mm².