Senior Power Integrity Engineer

You will own the power distribution network from voltage regulator output to die bump — impedance, IR drop, droop and decoupling across package and board. Senior IC role: you own the PDN numbers that power delivery, SI and the package team design against. What you will work on: • PDN design and closure for a multi-die AI accelerator package • DC IR, AC impedance, transient droop and electro-thermal analysis across die, package and board • Decoupling strategy and optimisation across on-die, package and board tiers • Package–board anti-resonance identification and mitigation • PDN noise to jitter translation, closed back into the SI budget Responsibilities: • Analysis & closure: Build and close DC IR, electro-thermal, AC impedance and transient PDN analysis from VR output through package to die bump. Set target impedance per rail and hold the design to it. • Chip power models: Work with CPM and workload current profiles to size on-die, package and board decoupling, and to predict droop across all three droop timescales. • Resonance & mitigation: Identify package–board anti-resonance and cavity behaviour, and drive the plane, via and decap changes that mitigate it. • SI coupling: Translate PDN noise into jitter through PHY supply sensitivity, and feed the result back into the channel budget. • Vendor & validation: Drive CPM and model requirements with IP, PHY and package vendors. Correlate against PDN impedance measurement and on-die droop telemetry, and support bring-up and power debug. Requirements: • 8+ years in power integrity for high-speed digital systems, including package-level PDN work • Hands-on with PDN extraction and simulation tools — Ansys SIwave/HFSS, Cadence Sigrity/Clarity or equivalent • Real experience with DC IR, target impedance, transient droop and decap optimisation on a high-current rail • Working knowledge of chip power models and how to apply workload current profiles • Comfortable reading a package substrate stackup and bump map, and reasoning about plane, via and cavity behaviour • Python scripting for automation and post-processing Nice to Have: • 2.5D, interposer, chiplet or advanced substrate PDN co-design • PDN impedance measurement and on-die margin or droop telemetry correlation • Electro-thermal co-simulation with the thermal team • Familiarity with OCP rack-scale platforms and high-current delivery architectures • Automated or AI-assisted engineering flows — PyAEDT, scikit-rf or similar Why Semidynamics? • Work for one of Europe’s most promising deep-tech semiconductor scale-ups. • Accelerated development path. • 4 days per week in the Barcelona office (city center), 1 day WFH. • 1 week of work from everywhere in the world. • Competitive package. • A collaborative, technical, and growth-oriented environment that values direct ownership and clear thinking.