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d-Matrix

Staff Analog Design Engineer, SerDes Clocking

Santa Clara, USAHybridPosted 1 month ago

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Job type
Full-time
Work mode
Hybrid
Level
Staff
Department
Engineering
Experience
5+ years experience
Posted
Aug 19, 2026

About the role

Role Overview

This is a hands-on, transistor-level analog design role owning the clocking subsystem of d-Matrix's high-speed SerDes on our IO chiplet — including the PLL, DLL, phase interpolator, high-frequency clock distribution, and clock and data recovery (CDR) loop. This block set most often determines whether a link closes, and you will personally carry your designs from specification through silicon characterization. The work spans porting proven clocking blocks to new process nodes and ground-up design for our next-generation link, partnering closely with datapath, DSP, digital, and firmware teams to close timing, jitter budgets, and calibration across the full SerDes macro.

What You Will Do

  • Own transistor-level design of low-jitter frequency synthesis — LC and/or ring PLL, including loop filter, charge pump or digital loop, VCO, and divider chain.
  • Own the phase interpolator and phase rotation scheme, including INL/DNL, glitch behavior, and interpolation resolution against the CDR's needs.
  • Design high-frequency clock distribution across the SerDes macro: buffer chains, duty-cycle correction, quadrature generation and correction, skew control, and supply isolation.
  • Define and verify CDR architecture and loop dynamics — bandwidth, jitter tolerance, jitter transfer, lock acquisition, and frequency offset tracking — modeling loop behavior in MATLAB, Python, or equivalent, and correlating against transistor-level and silicon results, in coordination with datapath and DSP owners.
  • Build phase-noise and jitter budgets for the link and own the analysis showing where jitter originates.
  • Build the verification environment for your blocks — PSS/HB and transient noise analysis, PVT corner coverage, Monte Carlo, and post-layout back-annotated simulation — and provide behavioral and Verilog-A models for full-chip verification.
  • Drive layout of your blocks in deep sub-micron nodes, with particular attention to inductor and VCO layout, shielding, symmetry, and supply/substrate isolation.
  • Take your blocks through silicon bring-up and bench characterization — phase noise, jitter tolerance, lock range — and correlate measured results against simulation.

What You Will Bring

  • BS/MS/PhD in Electrical Engineering, with 5+ years of hands-on analog and mixed-signal circuit design experience.
  • Demonstrated ownership of a low-jitter PLL, phase interpolator, or CDR loop through silicon in a high-speed SerDes link.
  • Deep knowledge of PLL architecture, loop dynamics, VCO design, and phase noise theory, along with working knowledge of CDR architectures and the loop analysis behind jitter tolerance and jitter transfer.
  • Practical experience with jitter decomposition and budgeting methodology, including quantifying contributors in simulation.
  • Circuit design experience in advanced FinFET or GAA process nodes, using industry-standard analog design and simulation tools and methodologies (e.g., Cadence Virtuoso, Spectre, Monte Carlo/corner analysis, post-layout simulation).
  • Silicon bring-up and bench debug experience with lab equipment such as phase noise analyzers, high-speed scopes, and BERTs.

Preferred

  • Die-to-die interconnect experience — UCIe, BoW, or a proprietary D2D PHY — including clocking architecture choices specific to short-reach, low-energy-per-bit links.
  • Forwarded-clock and matched-source-synchronous architectures alongside embedded-clock CDR.
  • Digital and hybrid PLL/CDR implementations, including the digital calibration around them.
  • Familiarity with relevant specifications: UCIe, OIF CEI-112G/224G, IEEE 802.3, PCIe Gen6/Gen7.
  • Experience porting a clocking block across process nodes, with a realistic sense of what that effort costs.
  • Participation in or contribution to standards bodies.

Equal Opportunity Employment Policy

d-Matrix does not accept resumes or candidate submissions from external agencies. We appreciate the interest and effort of recruitment firms, but we kindly request that individual interested in opportunities with d-Matrix apply directly through our official channels. This approach allows us to streamline our hiring processes and maintain a consistent and fair evaluation of al applicants. Thank you for your understanding and cooperation.