Power Integrations Releases 95%-Efficient, GaN-Based InnoSwitch3 Range of ICs

July 27, 2019 by Robin Mitchell

This week, Power Integrations has released their latest family of flyback switcher ICs that integrate GaN technology for more efficient power applications.

This week, Power Integrations has released their latest family of flyback switcher ICs that integrate GaN technology for more efficient power applications.

In fall of 2017, Power Integrations launched their InnoSwitch3 series of ICs. In March of last year, they began offering the InnoSwitch3-Pro specifically for fast-charging applications. Nearly a year ago, designs using the chipset were achieved compliance with USB PD 3.0 + PPS standard for use in USB-PD adapters.

Now, the company has announced a GaN (gallium nitride) version of the InnoSwitch3 ICs that can achieve up to a reported 95% efficiency, edging out their silicon counterparts.

Learn more about Power Integrations' newest chipset with this wide-bandgap semiconductor here.

Power Integrations Releases New InnoSwitch Devices

Many power companies are integrating GaN devices into their ICs thanks to this semiconductor's capability to switch large amounts of power with minimal losses.

This week, Power Integrations released several new products to their InnoSwitch line which incorporate GaN power transistors for flyback applications. Thanks to the use of GaN, the new device ranges are up to 95% efficient when switching powers as high as 100W while being enclosed in a small surface-mount InSOP-24D package.



The new product ranges incorporate the primary, secondary, and feedback circuitry into a single package that are needed in offline CV/CC flyback circuits. The new range of devices include the InnoSwitch3-EP, the InnoSwitch3-CP, and the InnoSwitch3-CE which each have their own specialties.

While each InnoSwitch3 family has its own applications they also share some key characteristics:

  • EcoSmart: These devices consume less than 30mW with no load to easily meet global efficiency regulations.
  • Protection Systems: Short-circuit, open SR FET-gate detection, and under/over voltage protection are standard.
  • Compliance: The families feature halogen-free and RoHS compliant packages.


Relevant Range Specs

The InnoSwitch3-EP range of devices includes a multimode quasi-resonant / CCM flyback controller, high voltage switch, and secondary-side sensing and synchronous rectification driver as well as integrated FluxLink, HIPOT-isolated, and feedback link with an optional auto-restart undervoltage protection.

The InnoSwotch3-CP range of devices are up to 94% efficient across the entire power range and also include quasi-resonant / CCM flyback controller, accurate CV/CC/CP, and instantaneous transient response 0%-100%-0% load step while available with several optional features including cable-drop compensation, auto-restart and latching fault, and multiple output undervolt fault thresholds.

The InnoSwitch3-Pro incorporates a multimode quasi-resonant / CCM flyback controller, high voltage switch, and secondary-side sensing and synchronous rectification driver as well as an integrated 3.6V supply for external microcontrollers, instantaneous trainset response, and is optimized for efficiency across the entire line and load range. But the InnoSwitch3-Pro also integrates a digitally controlled I2C interface that allows for MCUs to dynamically adjust the power supply voltage and current as well as fault monitoring.


An example circuit for the InnoSwitch3-Pro


InnoSwitch3 Applications

The InnoSwitch3 range of devices has a wide range of power applications, including USB-PD, high-current chargers, mobile chargers, set-top boxes for televisions, displays, appliances, networking, and gaming products.

Since energy conservation and efficiency is increasingly becoming a key selling point of consumer products, it can be said that the InnoSwitch3 is a desirable flyback controller for the latest low-power products.

According to Balu Balakrishnan, President and CEO, “GaN is a pivotal technology offering significant efficiency and size benefits over silicon. We anticipate a rapid conversion from silicon transistors to GaN in many power applications. InnoSwitch3 has been the clear technology leader in the offline switcher IC market since we launched the silicon variants 18 months ago, and the new GaN-based ICs further extend our lead by advancing both the efficiency and power capability of our flyback products.”

What's the Fuss about GaN?

Silicon is the workhorse semiconductor material for a wide range of reasons, including its price, ease of technology implementation, maturity, and manufacturing properties. However, when it comes to power electronics, we have in many ways effectively reached silicon’s physical limitations. With energy efficiency now at the center of a wide range of modern products, silicon-based designs are feeling the power pinch.

However, recent developments and improvements in gallium nitride transistor technology are now seeing GaN as a viable alternative semiconductor material, especially in power applications.

But why is GaN desirable over silicon in power applications?

Firstly, GaN-based devices can conduct as many as 10,000 times more efficiently than silicon, which results in significantly smaller power losses. Secondly, GaN devices can be fabricated in silicon-based facilities with minimal equipment change. Thirdly, the cost of GaN devices is inherently lower than producing silicon MOSFET devices.

Of course, if GaN is so brilliant, then why is GaN not being used in processors and microcontrollers instead of silicon? This is a complicated question but the answer comes down to several factors, including the difficulty of producing P-type GaN devices and the need for low-K materials for high-speed electronics. The miniaturization of GaN on a large scale (i.e., 1 billion+ IoT devices) is not as mature as silicon.

But for a simple comparison, GaN is preferable in power electronics over silicon because GaN:

  • Has a lower on resistance
  • Can switch faster than silicon devices (making them preferable for radio applications)
  • Has a lower capacitance
  • Requires less power to drive a device



With the release of their 91%-efficient InnoMux chipset this spring, it's clear the Power Integrations is looking to make a big impact on high-efficiency ICs. If you've worked on a design that puts a high premium on efficiency, share your experiences in the comments below.

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