Senior / Staff / Principal Analog Design Engineer - PLL

18 hours ago Be among the first 25 applicants Get AI-powered advice on this job and more exclusive features. Flux Computing designs and manufactures optical processors to train and run inference on large AI models. Join us in London to be part of a highly motivated and skilled team that thrives on delivering impact and innovation at speed. The Role We’re searching for a Senior/Staff/Principal Analog Design Engineer with a strong focus on CMOS phase‑locked loops (PLLs) and clock‑distribution networks. You will architect, design and bring to production an ultra‑low‑jitter clocking subsystem that fans out precise multi‑GHz clocks to more than 100 parallel optical‑compute channels inside the OTPU. The work spans fractional‑N synthesisers, on‑chip loop filters, de‑skew circuits and high‑integrity clock‑tree distribution—all while meeting stringent power, spur and phase‑noise budgets required by next‑generation AI workloads. Responsibilities Architect, design and verify wide‑bandwidth fractional‑N PLLs (multi‑GHz output) including VCOs, charge pumps, loop filters and frequency dividers to achieve sub‑100fsrms integrated jitter. Develop clock‑distribution networks—buffer trees, deskew circuits, differential or CML fan‑outs—that deliver phase‑aligned clocks to >100 destination blocks with Co‑optimise the PLL with packaging, board, and power‑delivery teams to minimise supply‑induced jitter, crosstalk and electromagnetic coupling in a dense optical‑compute environment. Create behavioural and transistor‑level models (Verilog‑A / SPICE) for system‑level co‑simulation of timing budgets, ensuring reliable link margins across PVT corners. Mentor junior engineers, lead rigorous design reviews, and champion best‑practice methodologies for low‑jitter analog design and measurement. Track and inject into the team the latest advances in PLL architectures, adaptive biasing, clock‑mesh techniques, and on‑chip jitter‑monitoring. Skills & Experience 7+years of industry experience designing production CMOS PLLs, CDRs or other precision clock generators. Demonstrated success achieving sub‑100fsrms jitter and Mastery of analog/RF EDA tools for schematic capture, SPICE‑/S‑parameter simulation, layout, parasitic extraction and mixed‑signal verification. Bachelor’s degree in Electrical Engineering (or related); Master’s / PhD preferred. Excellent problem‑solving, communication and cross‑disciplinary collaboration abilities. Thrive in rapid‑iteration, high‑ownership environments; bring a portfolio of patents, publications or personal projects that showcases innovative clock‑generation or high‑speed analog design. Competitive salary: £135k+, depending on experience. Stock options in a rapidly growing AI company. Based in our new 5,000 sq. ft. office in the AI hub of Kings Cross, London. To foster collaboration in our high-growth environment, we require all employees to work from our London HQ and live within a 45-minute commute. We offer an extra £24,000/year incentive for those living within 20 minutes. Comprehensive healthcare insurance. Private access to our in-house 3D printer. If you are passionate about pushing the boundaries of what\’s possible in AI and thrive in a high-energy, fast-paced environment, we want to hear from you. Apply now to join Flux and be a key player in shaping the future of computing. Seniority level Seniority level Not Applicable Employment type Employment type Full-time Industries Semiconductor Manufacturing Referrals increase your chances of interviewing at Flux Computing by 2x Get notified about new Analog Design Engineer jobs in London Area, United Kingdom . Greater London, England, United Kingdom 3 weeks ago London, England, United Kingdom 1 day ago Rainham, England, United Kingdom 2 days ago London, England, United Kingdom 3 weeks ago City Of London, England, United Kingdom $50,000.00-$55,000.00 2 days ago London, England, United Kingdom 6 days ago London, England, United Kingdom 3 weeks ago City Of London, England, United Kingdom 3 days ago Saffron Walden, England, United Kingdom £38,000.00-£40,000.00 3 days ago Battersea, England, United Kingdom 2 days ago London, England, United Kingdom 1 day ago London, England, United Kingdom 4 weeks ago City Of London, England, United Kingdom £70,000.00-£80,000.00 1 week ago London, England, United Kingdom 3 days ago London, England, United Kingdom 2 months ago City Of London, England, United Kingdom 20 hours ago Uxbridge, England, United Kingdom 6 days ago London, England, United Kingdom 1 month ago We’re unlocking community knowledge in a new way. Experts add insights directly into each article, started with the help of AI. #J-18808-Ljbffr