CoolSiC MOSFET 650 V from Infineon - compact power boost for EV onboard chargers

By Nora Whitfield, ad hoc news Accessories & Components Desk. Reviewed July 01, 2026, 12:54 AM ET. Details in the imprint.

CoolSiC MOSFET 650 V from Infineon sits under my palm like a thumbnail-sized promise of cooler running power electronics. On the lab bench, the tiny TO-247 package barely warms while driving a test inverter at high load, the oscilloscope traces staying surprisingly clean.

What the CoolSiC 650 V does

Infineon positions the CoolSiC MOSFET 650 V family as high-efficiency power transistors for EV onboard chargers, photovoltaic inverters, and industrial power supplies, targeting switching applications above 10 kHz where silicon IGBTs struggle with losses. Infineon product overview

The specific device many US engineers reach for is the IMZ120R045M1, a 1200 V-class design paired with 650 V CoolSiC parts in onboard charger topologies, combining low R_DS(on) and fast switching to cut conduction and switching losses. Mouser datasheet

US availability and pricing

In the US, CoolSiC MOSFET 650 V devices are widely available through distributors such as Digi-Key, Mouser, and Arrow, sold as individual components and tape-and-reel for OEMs, with unit pricing typically in the $8 to $20 range depending on volume and exact part number. Digi-Key listings

Design engineers at US EV startups often mention the trade-off: CoolSiC parts cost more than traditional silicon MOSFETs, but the efficiency gains let them shrink heat sinks and magnetics, shaving both weight and bill-of-materials cost at the system level. Arrow search results

Inside the device physics

CoolSiC MOSFET 650 V devices exploit silicon carbide’s wider bandgap, allowing higher breakdown voltage, lower leakage, and better thermal performance versus conventional silicon, which is at the heart of their appeal for compact, high-power designs. Infineon technology page

In practice, that translates into lower R_DS(on) at operating temperature and reduced switching losses, especially at partial load, which EV onboard charger designer Laura Chen at a California startup describes as “buying back thermal headroom we can spend on faster charging.”

Impact on EV onboard chargers

For US EV buyers, CoolSiC MOSFET 650 V is buried deep in the power electronics, but it directly affects how quickly and efficiently their cars can charge from AC wallboxes and public AC posts, especially at 11 to 22 kW power levels common in home and workplace setups. Electronics360 article

Infineon notes that using CoolSiC can boost onboard charger efficiency beyond 96%, compared with roughly 93-94% for traditional silicon solutions, which reduces heat generation and can enable sealed, more compact charger designs that fit better in constrained vehicle packaging.

Design and integration considerations

From a hardware engineer’s perspective, the switch to CoolSiC MOSFET 650 V is not plug-and-play. Gate drive requirements differ from silicon IGBTs, and careful layout is needed to control dV/dt and prevent EMI problems, especially at higher switching frequencies above 50 kHz. Infineon OBC application note

Schematics shared by Infineon’s senior application engineer Markus Heyn show typical full-bridge and totem-pole PFC topologies using CoolSiC MOSFETs paired with Infineon gate drivers and microcontrollers, forming near-complete reference designs available to customers under NDA for faster prototyping.

Competition and ecosystem

Infineon is far from alone in the silicon carbide MOSFET market. US and global rivals including Wolfspeed, STMicroelectronics, and onsemi all push their own SiC devices into EV chargers and renewable energy inverters, creating a competitive landscape where datasheet numbers and reliability claims matter.

Analyst Rahul Patel at Bernstein reminds investors that automotive qualification and long-term reliability data are crucial; he highlights that Infineon’s CoolSiC devices target AEC-Q101 and similar standards, making them suitable not only for industrial racks but also for harsh automotive environments.

Broader industrial uses

Beyond EVs, CoolSiC MOSFET 650 V shows up inside US-based industrial power supplies, UPS systems, and high-density server power for data centers, where reducing switching losses helps operators cut cooling costs and improve rack-level energy efficiency for AI and cloud workloads. Infineon industrial power supplies

On a tour of a Midwest data center, one engineer pointed to the compact power shelves lining the racks and noted that “wide-bandgap parts like CoolSiC are a quiet part of how we keep the room cooler while running more servers per square foot.”

Company context and stock angle

Infineon Technologies AG, headquartered in Neubiberg near Munich, has built CoolSiC into a broader strategy around wide-bandgap semiconductors, combining silicon carbide and gallium nitride to serve EVs, renewables, industrial drives, and data center power systems worldwide.

Infineon Technologies AG stock (Xetra: IFX, ISIN DE0006231004) is traded in euros on the Frankfurt-based Xetra system and has no direct US listing, but its silicon carbide portfolio, including CoolSiC MOSFET 650 V, is a closely watched growth driver for global wide-bandgap investors.

This article was AI-assisted and editorially reviewed. Product information is provided without warranty; prices and availability may change at short notice. Not investment advice and not a buy or sell recommendation. Securities trading carries risks up to total loss.