On September 29, 2026 in Automotive, Computing, Industrial, Power, Wide Bandgap by Microchip Technology

Image Source: Mouser

By Kevin Dykyj, Senior Digital Marketing Specialist, Microchip Technology, for Mouser

Scaling Power Without Overengineering

As power electronics move into the medium-voltage domain, designers are discovering that scaling power is no longer just a matter of selecting a bigger device. Higher bus voltages introduce new constraints around insulation, switching behavior, layout, and long-term reliability. In many systems, these factors dominate the design effort well before current limits are reached.

An alternative design philosophy is gaining traction. Instead of scaling primarily through current, designers are building systems from voltage-rated power blocks that can be repeated and combined. In this approach, 3.3kV silicon carbide power modules form the backbone of scalable architectures, allowing systems to grow by replication rather than reinvention.

Traction Auxiliary Power Systems: Designing for the Real Load

Auxiliary loads are typically supplied from the same high-voltage DC bus that feeds the traction inverter. While bus voltage is substantial, associated current levels are far lower than those seen in propulsion stages. This imbalance makes auxiliary systems well suited to voltage-optimized power stages rather than high-current devices designed for traction duty.

Using 3.3kV SiC modules allows auxiliary converters to connect directly to the traction bus without stacking devices in series (Figure 1). Operating at higher switching frequencies reduces magnetic component size and enables higher power output by replicating proven converter stages.

Figure 1: Block diagram of a traction auxiliary system showing modular high-voltage DC-DC and inverter stages. >>Click to read the entire article at Mouser

Auxiliary converters often operate continuously in harsh thermal and mechanical environments for decades. In this context, insulation robustness, partial-discharge performance, and stable switching behavior can matter more than headline current capability. High-voltage, moderate-current modules align more closely with these long-term requirements than oversized propulsion-class devices.

Solid-State Transformers in Data Centers: Voltage as the Organising Principle

Solid-state transformer architectures are modular by necessity, typically built from multiple medium-voltage conversion cells that share the load and provide isolation. In these systems, allowable DC-link voltage largely determines how much power each cell can process, with voltage rating and switching performance setting practical design limits.

Using 3.3kV SiC power modules enables higher DC-link voltage operation, increasing the power handled by each conversion cell. As a result, fewer modules are required to achieve a given system power level (Figure 2). Reducing module count simplifies interconnections, lowers system losses, and improves overall efficiency while keeping control and protection schemes manageable.

Figure 2: Simplified solid-state transformer architecture using 3.3kV MOSFETs with higher DC-link voltage >>Click to read the entire article at Mouser

When fewer, higher-power conversion cells share a common electrical and mechanical foundation, maintenance is simplified and system expansion is less disruptive compared to architectures built from many lower-voltage or heavily paralleled high-current stages.

Medium Voltage Ultrafast Chargers: AC-DC PFC and DC-DC Conversion

Medium-voltage-fed ultra-fast chargers are emerging as a practical path to megawatt-class charging, allowing systems to draw power directly from MV infrastructure while reducing input current, cabling losses, and upstream equipment size. These architectures typically use an AC/DC power-factor-correction stage followed by isolated DC/DC conversion, with each stage optimised around voltage rather than extreme current.

In these systems, the most critical semiconductor parameter is drain-to-source voltage rating (VDSS). Using 3.3kV devices enables higher DC-link voltage operation, increasing the power handled by each conversion stage. This capability simplifies system architecture by reducing the number of series-connected devices and lowering the total module count required to reach target power levels.

Both the AC/DC PFC stage and the primary side of the DC/DC stage (Figure 3) typically operate in resonant or quasi-resonant modes that achieve soft switching across a wide operating range. Under these conditions, switching losses are reduced and conduction loss becomes dominant, making lower on-resistance devices particularly beneficial at the system level.

Figure 3: MV-Fed USC Charger in 420 kW Series Input Parallel Output Configuration with Six 70 kW Stages >>Click to read the entire article at Mouser

The secondary side of the isolated DC/DC stage operates at lower voltage and higher current, shifting design emphasis toward current handling. On the MV-fed front end and primary-side stages, however, the combination of high DC-link voltage and soft-switching operation favors lower RDS(on) devices, especially in solid-state transformer and ultra-fast charging architectures.

Why Voltage-Optimised Modules Are Finding Their Place

Across these applications, a common theme emerges. In many medium-voltage systems, current is not the limiting factor. Designers instead focus on insulation, switching behavior, layout constraints, and qualification effort.

High-current SiC modules remain essential where large motor currents dominate, such as in main traction inverters. In the auxiliary, conversion, and distribution stages, however, high-voltage modules optimised for moderate current often lead to simpler architectures and more predictable scaling.

By treating 3.3kV SiC modules as standardised building blocks, engineers can scale systems through repetition, reducing design risk, shortening validation cycles, and creating architectures that are easier to extend as requirements evolve.

Building Scalable Systems One Voltage-Rated Module at a Time

As medium-voltage power systems expand across transportation, data centers, and renewable energy, modular design is moving from theory into practice. High-voltage SiC modules make it possible to design power stages around voltage constraints first, then scale power by replication rather than escalation.

Solutions such as the HV-D3 3.3kV mSiC® power modules from Microchip Technology reflect this approach. Rather than targeting maximum current, they focus on voltage margin, insulation integrity, and consistent switching performance. In traction auxiliary systems, solid-state transformers and renewable energy converters, this alignment supports architectures that scale cleanly and predictably.

As designers look ahead to higher voltages and more distributed power systems, building around voltage-optimised modules offers a practical path forward that balances efficiency, reliability, and long-term flexibility.

>>Click to read the entire article at Mouser

Author Bio - Kevin Dykyj is a Principal Digital Marketing Specialist at Microchip Technology with a focus on power semiconductor solutions. His background includes developing technical content and product positioning focused on SiC, IGBTs, and power modules. He brings a technically grounded perspective shaped by real-world system considerations in industrial, data center, sustainability, and electrification applications.

Microchip Technology Inc. is a leading provider of microcontroller, mixed-signal, analog and Flash-IP solutions, providing low-risk product development, lower total system cost and faster time to market for thousands of diverse customer applications worldwide. Headquartered in Chandler, Arizona, Microchip offers outstanding technical support along with dependable delivery and quality.