GaN Process Brings SiC-Level Efficiency to 1,700-V Multi-Output Switcher

What you’ll learn:

• Rated for a maximum input of 1,700 V, Power Integrations’ GaN-based multi-output switching regulators support reliable operation at the higher supply voltages increasingly used by automotive, industrial, and renewable-power systems.
• Thanks to an architecture that supports zero-voltage switching and tight voltage regulation, the converters can deliver end-to-end efficiencies in excess of 90% across their entire operating range.

Power Integrations’ (PI) introduction of the industry’s first commercial gallium-nitride (GaN), 1,700-V power-conversion devices brings another silicon-carbide (SiC) alternative to the table. Available with up to three independently regulated outputs, the 1,700-V InnoMux-2 single-stage, offline power-supply ICs can be used with input voltages of in excess of 1,200 V DC. Their high levels of reliability are what’s sought after for today’s automotive chargers, solar inverters, three-phase meters, and many other types of industrial power systems (Fig. 1).

The devices expand the range of PI’s InnoMux-2 series by integrating switching elements rated for a maximum safe surge voltage region (SSVR) of 1,700 V. When a standard 80% derating value is applied, it’s able to operate reliably at up to 1,360 V DC (Fig. 2). “A 1700-V rating is substantially higher than any other commercially available GaN HEMT that we are aware of,” said Ezgi Dogmus, Activity Manager, Compound Semiconductors at Yole Group.¹

The 1,700-V InnoMux-2 IC uses PI’s FluxLink secondary-side regulation (SSR) digital isolation communications technology, paired with its patented multiplexing technique, to precisely monitor and control the power being fed to each of the converter’s switching outputs. This enables the converter to support zero-voltage-switching (ZVS) operation that virtually eliminates switching losses.

The device’s single-stage conversion architecture eliminates the losses incurred by stackFET circuits and other earlier technologies normally used to achieve operating voltages in excess of 750 to 1,000 V (Fig. 3).

In addition, the converter’s precise on-chip regulation eliminates the need for external post regulator stages, which can improve end-to-end system efficiency by as much as 10%. As a result, each of the device’s outputs is able to operate at over 90% efficiency throughout its operating range while delivering one 1% (or better) accuracy (Fig. 4).

While it’s still necessary to use SiC or IGBT devices for high-power, high-voltage applications, such as traction inverters, Power Integrations’ 1,700-V integrated converters can economically meet the requirements of applications that need to efficiently derive 65 W worth of AC or 65 W of DC from a high-side rail.

As with all of PI’s InnoMux-2 products, the 1,700-V version is housed in an INSOP package. The only difference is that it uses a D-Style configuration, which adds more distance between drain and gate pins to prevent leakage and arc-over when operating at these higher voltages. 

Availability & Resources for the Switcher IC

Pricing for the InnoMux-2 1,700-V ICs starts at $4.90 for 10,000-unit quantities. A reference design, RDR-1053, which describes a 60-W dual-output (5 and 24 V) power supply, can be downloaded from the company’s website at no cost.

For sample ICs, evaluation boards, and further information, contact a Power Integrations sales representative or one of the company’s authorized worldwide distributors: DigiKey, Mouser, Newark, and RS Components.

References

1. Power GaN report, Yole Intelligence, 2024