New Industry Products

Power Integrations Claims its New AEC-Q100 Qualified Switcher ICs Are First to Incorporate a SiC MOSFET

February 14, 2022 by Gary Elinoff

The devices can efficiently deliver power to battery and fuel-cell passenger EVs, in addition to electric buses and trucks.

With 800 V rails now common in electric vehicles, Power Integrations (PI) has introduced two new 1700 V switching power supply ICs, the first it says to both incorporate silicon carbide (SiC) primary switching MOSFETs and meet automotive standards. Members of PI's InnoSwitch™3-AQ family, the new ICs can deliver up to 70 watts of power. And with their 1700 V capacity, they provide the necessary margin of safety for use in not just EVs, but also a wide range of industrial power applications. 


The InnoSwitch3-AQ family. The dotted line depicts the FluxLink isolation between primary and secondary sides of the circuit. Image used courtesy of Power Integrations


The switcher ICs, available in a compact InSOP-24D package, employ PI’s FluxLink feedback link, providing reinforced isolation up to 5000 VRMS between the high-voltage primary side and the lower-voltage secondary. FluxLink technology facilitates direct sensing of the output voltage, which allows for both accurate regulation and rapid response to transients.


Wide Bandgap Semiconductors

Wide bandgap semiconductors, such as those fabricated of SiC or GaN (gallium nitride), can switch at far greater speeds than old-school silicon devices. This allows for smaller filtering components, saving both weight and space, which is why these new technologies are driving a paradigm shift across the entire power electronics marketplace.

In EVs, for example, Power Integrations’ InnoSwtich3-AQ devices can quickly operate at voltages ranging between 30 and 1000 volts, critical should the main traction inverter’s emergency power supply be called upon at a moment’s notice, said Peter Vaughan, director of the company’s automotive business development. 



The InSOP-24D package, along with a range of EV applications. Image used courtesy of Power Integrations


“Our Sic-based InnoSwitch3-AQ devices can handle this vast range with incredible ease,“ Vaughan said. “InnoSwitch devices allow the electronics to safely sip from the firehose of energy available on the main bus.” 


Efficiency and No Load Power Consumption

Synchronous rectification on the secondary side enables the units to offer a power efficiency of over 90%. At the same time, this design allows for no load consumption of only 15 mW, which is highly desirable in applications such as battery management systems (BMS).


Regulation and Protection

Output regulation is less than ±5%, which includes responses to variations due to line or load shifts, temperature variations and, most importantly, to voltage transients. There are protections for load overvoltage, overcurrent and line undervoltage, in addition to a provision for thermal shutdown.


The Two Versions

The INN3947CQ and the INN3949CQ sport the following output powers at the specified voltages.


Output Power
  10 VDC 60 VDC  400 VDC  800 VDC 
INN3947CQ 10 23 50  50 
INN3949CQ 10  40  70  70 


Non-Automotive Uses

The new switchers will also find application in other demanding, electrically noisy environments, where they can reduce the BOM count otherwise required by discrete controller-plus-MOSFET designs, saving board space and reducing cost. These applications include battery storage, renewable energy, and industrial motor drives.


Getting to Market Faster

To aid engineers with these new devices, PI offers the RDR-919Q, a reference design for 60 W power supplies. Employing the INN3949CQ, this switcher design operates from inputs ranging from 50 to 1,000 VDC, supplying outputs of 50, 100, 200 or 300 to 1,000 VDC. 


Feature image used courtesy of Curtiss-Wright Industrial Division