Why join Upscale, Inc.
Upscale, Inc., is building the high-performance infrastructure powering the next generation of artificial intelligence. Backed by over $500M in funding and rapid global adoption, we are scaling systems designed for the world’s most demanding AI workloads.
We focus on first-principles engineering across silicon, systems, and networking—where performance, scale, and execution are critical. Our team is talent-dense and high-performing. We value ownership, technical rigor, and speed, and we offer the opportunity to work on foundational problems with immediate, real-world impact.
If you’re looking to do high-impact work, move fast, and help define the infrastructure behind the future of AI—Upscale is where you can produce meaningful work at the frontier—and operate at a high standard.
About the Role
We are building a world-class SerDes engineering organization to enable next-generation, ultra-high-speed connectivity for AI data centers and high-performance computing.
We are seeking an exceptional technical leader to define the clocking architecture for next-generation SerDes, spanning ultra-low-jitter phase-locked loops (PLLs) and high-performance clock distribution networks.
This is a senior individual contributor role for a recognized expert in high-speed clocking technology who can drive architectural innovation, lead critical circuit development, and solve some of the most challenging jitter, coupling, and power-efficiency problems in advanced CMOS.
You will establish the clocking architecture and design methodology for our next-generation SerDes platform, working across analog, mixed-signal, digital, layout, and system teams to deliver exceptional timing performance in advanced process technologies at 5nm and below.
Responsibilities:
- Clocking Architecture: Define and drive the end-to-end clocking architecture for next-generation SerDes, including PLLs, clock generation, multiphase clocking, clock distribution, and integration with transmitter and receiver subsystems.
- Ultra-Low-Jitter PLL Design: Lead the architecture and development of ultra-low-jitter PLLs targeting less than 100 fs RMS integrated jitter in advanced CMOS technologies at 5nm and below, meeting stringent system-level timing and noise requirements.
- PLL Architecture Innovation: Evaluate and develop hybrid, digital, and other advanced PLL architectures, making informed trade-offs among jitter, power, area, tuning range, robustness, and implementation complexity.
- Multi-PLL Coupling Management: Develop architectural and circuit-level solutions to mitigate coupling among multiple PLLs and clock-generation blocks, including supply coupling, substrate noise, electromagnetic interactions, reference spurs, and clock-to-clock interference.
- Power-Efficient Clock Distribution: Define and implement advanced clock distribution architectures, including resonant clocking techniques, to reduce clocking power while maintaining stringent jitter, skew, phase-noise, and timing requirements.
- EM Analysis and Optimization: Use electromagnetic simulation and extraction tools to analyze and optimize inductors, resonant networks, clock distribution structures, coupling paths, and high-frequency interconnects.
- Modeling and Verification: Develop SystemVerilog-based behavioral models, verification environments, and architectural models for PLLs and clocking subsystems to enable early system integration, design exploration, and verification of key performance requirements.
- Cross-Functional Technical Leadership: Partner with SerDes TX, RX, ADC, digital, AMS layout, package, and silicon validation teams to optimize overall link performance and ensure clocking architecture decisions align with system requirements.
- Silicon Execution and Correlation: Drive design reviews, implementation strategy, silicon characterization, jitter and phase-noise analysis, and simulation-to-silicon correlation.
Qualifications:
- MS or PhD in Electrical Engineering or a related field, with extensive experience in high-performance analog and mixed-signal IC design.
- Demonstrated success designing and delivering ultra-low-jitter PLLs (100 fs-class RMS integrated jitter) in advanced CMOS technologies at 5nm or below.
- Deep expertise in PLL architecture and circuit design, including phase detectors or phase-frequency detectors, charge pumps where applicable, loop filters, oscillators, frequency dividers, and loop dynamics.
- Strong understanding of phase noise, integrated jitter, reference spurs, loop stability, supply-induced jitter, and the impact of clock quality on high-speed SerDes performance.
- Proven ability to define clocking architectures and translate stringent system-level jitter requirements into circuit-level specifications and implementation strategies.
- Experience with clock distribution design and the management of coupling, skew, power integrity, and electromagnetic interactions.
- Hands-on experience with electromagnetic simulation and extraction tools for analyzing high-frequency circuits and passive structures.
- Experience developing SystemVerilog-based behavioral models and verification environments for PLLs or other mixed-signal clocking systems.
- A strong track record of technical leadership, architectural decision-making, and successful silicon delivery.
- Direct experience developing clocking solutions for 100G+ per-lane SerDes.
- Experience with hybrid PLL architectures, digital PLLs, digitally assisted analog PLLs, or other advanced clock-generation techniques.
- Demonstrated expertise in resonant clock distribution, including resonant network design, energy recovery, clock power optimization, and associated implementation trade-offs.
- Experience managing interference among multiple high-performance PLLs operating within a shared die, including reference distribution, supply isolation, substrate coupling, and electromagnetic coupling.
- Proficiency with tools such as Cadence EMX, Ansys HFSS, or equivalent electromagnetic solvers.
- Experience with advanced-node physical implementation, custom layout, parasitic extraction, and silicon debug.
- Recognized technical contributions through successful silicon products, patents, publications, or industry-leading clocking innovations.