About the role: We are building a first-of-its-kind integrated PSU+BBU rack power shelf that collapses the traditional two-shelf architecture (separate power supply and battery backup) into a single, high-density platform powered by solid-state battery technology. This shelf will compete directly with incumbent rack power offerings from Delta, LITEON, and similar vendors, targeting hyperscale AI data center deployments.

As Power Electronics Lead, you will own the complete power conversion architecture - from AC mains or 48V DC bus input through regulated output rails, including the bidirectional charge/discharge path for the integrated solid-state battery pack. You are the chief engineer for the power stage and the technical decision-maker whose topology choices cascade to every other discipline on the team.

Why this role matters: Your architecture decisions define the entire product. Whether the battery sits in-line or on a sidecar bus, whether you go GaN at 48V or Si at 12V, whether the hold-up transfer is sub-millisecond or requires a brief interruption - every downstream engineer builds on top of your choices. This is a rare opportunity to design a power platform from a blank sheet with a technology (solid-state batteries) that fundamentally changes what's possible at rack level.

What you'll do:

• Architect the end-to-end power conversion topology (AC-DC front end, intermediate bus, DC-DC output stage, bidirectional battery converter path)
• Lead topology trade-off analysis: LLC resonant, phase-shifted full bridge, hybrid approaches, in-line vs. parallel sidecar battery integration
• Design magnetics (planar transformers, coupled inductors) and select power semiconductors (GaN/SiC FETs, diodes) with thermal derating analysis
• Define and drive efficiency targets (97%+ titanium-class at rack load) and power density goals within a lOU or 20U shelf envelope
• Collaborate closely with the firmware/embedded engineer on digital control loop implementation (voltage/current mode compensation, loop bandwidth, phase margin)
• Work with the battery systems engineer to define the charge/discharge power path, voltage window, and current limits for solid-state cells
• Design protection circuits (OCP, OVP, OTP, short-circuit) and define fault response behavior
• Bring up and validate prototype power stages on the bench, iterating through bringup, thermal characterization,and efficiency optimization
• Interface with the PCB layout contractor to ensure EMI-conscious layout, proper creepage/clearance,and power plane integrity

Skills you'll need:

• 10+ years designing multi-kW AC-DC or DC-DC power converters that shipped in volume
• Deep expertise in at least two converter topologies (LLC, PSFB, DAB, CLLC, or equivalent)
• Hands-on magnetics design experience (core selection, winding strategy, loss modeling)
• Experience with digital power control (working with DSP/MCU-based compensators, not just analog)
• Track record in server PSU, telecom rectifier, EVonboard charger, or comparable high-density power product
• Proficiency with simulation tools (PLECS, LTspice, Simplis, PSIM, or equivalent)
• Comfortable leading technical direction and mentoring a small cross-functional team

Nice to have:

• GaN or SiC wide-bandgap device design experience
• Familiarity with 48V or high-voltage DC bus architectures
• Experience with bidirectional power converters (critical for integrated battery path)
• Knowledge of OCP Open Rack/ ORv3 power delivery specs
• Prior exposure to battery charging systems (CC-CV profiles, temperature-dependent rate limits)
• Experience with hardware-in-the-loop testing (Typhoon HIL, PLECS RT Box)

ONSITE: This position is required to work onsite 5 days per week to meet the minimum essential duties and requirements of this position. As an on-site R&D and manufacturing operations organization, in-person face to face interaction is essential to building authentic relationships, trust, teamwork, and collaboration.

Compensation & Benefits: Expected salary range for this role is from $155,300 to $236,900, and a final salary will be determined by the candidate's experience and educational background. QuantumScape also offers an annual bonus and a generous RSU/Equity package as part of its compensation plan. In addition, we do offer a tremendous benefits plan including employee paid health care, Employee Stock Purchase Plan (ESPP), and other benefits.