U

Upscale AI

High-performance AI networking hardware and software

Distinguished Engineer - Serdes Clocking

Silicon & ASIC DesignConfirmed live in the last 24 hours
Full-timeSanta Clara, CA, USA$313k - $353k /yrIn-person

About the Job

Requirements

  • A master's or PhD in Electrical Engineering or a related field, with extensive experience in high-performance analog and mixed-signal integrated circuit design.
  • Demonstrated success designing and delivering ultra-low-jitter phase-locked loops (100 femtosecond-class root-mean-square integrated jitter) in advanced CMOS technologies at 5 nanometers or below.
  • Deep expertise in phase-locked loop 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 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 phase-locked loops 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 phase-locked loop architectures, digital phase-locked loops, digitally assisted analog phase-locked loops, 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 phase-locked loops 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.

Responsibilities

  • Define and drive the end-to-end clocking architecture for next-generation SerDes, including phase-locked loops, clock generation, multiphase clocking, clock distribution, and integration with transmitter and receiver subsystems.
  • Lead the architecture and development of ultra-low-jitter phase-locked loops targeting less than 100 femtoseconds RMS integrated jitter in advanced CMOS technologies at 5 nanometers and below, meeting stringent system-level timing and noise requirements.
  • Evaluate and develop hybrid, digital, and other advanced phase-locked loop architectures, making trade-offs among jitter, power, area, tuning range, robustness, and implementation complexity.
  • Develop architectural and circuit-level solutions to mitigate coupling among multiple phase-locked loops and clock-generation blocks, including supply coupling, substrate noise, electromagnetic interactions, reference spurs, and clock-to-clock interference.
  • 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.
  • Use electromagnetic simulation and extraction tools to analyze and optimize inductors, resonant networks, clock distribution structures, coupling paths, and high-frequency interconnects.
  • Develop SystemVerilog-based behavioral models, verification environments, and architectural models for phase-locked loops and clocking subsystems to enable early system integration, design exploration, and verification of key performance requirements.
  • Partner with SerDes transmitter, receiver, analog-to-digital converter, digital, analog/mixed-signal layout, package, and silicon validation teams to optimize overall link performance and align clocking architecture decisions with system requirements.
  • Drive design reviews, implementation strategy, silicon characterization, jitter and phase-noise analysis, and simulation-to-silicon correlation.

About the Company

Upscale AI

High-performance AI networking hardware and software

Upscale AI builds a full-stack, high-performance AI networking platform to scale up GPU compute. It designs purpose-built silicon chips and a software orchestration layer that connects thousands of GPUs into a single, unified compute engine. The system is optimized for the heavy data movement and bursty traffic of large language model training and inference, enabling fast, scalable AI workloads. Unlike traditional, vendor-driven networking stacks, Upscale AI offers open-standard networking powered by silicon and software, and participates in consortia like UEC and SONiC to ensure interoperability across different hardware environments. Its customers include global hyperscalers, AI-first enterprises, and sovereign cloud providers who need large-scale, interoperable AI clusters without lock-in. The company’s goal is to democratize AI infrastructure by delivering high-performance, open-standard solutions that let organizations build and operate massive AI clusters more efficiently.

Company size
201-500
Company stage
Series A
Total funding
$490M
Headquarters
Santa Clara, CA
Founded
2024

Recently Posted Jobs

Explore more opportunities at Upscale AI

See more jobs