Interested — this is the kind of board I do.
Background: US-based circuit design engineer, 30 years. Day job is hardware
at a tech company; my own practice takes commercial and medical work.
Recent example: a 12-layer, 6,100-pin RFSoC board (Gen3 RF data converter,
DDR, 10GbE).
A few things I'd want to get right here, so you can judge whether I'm the
right person:
1. The parallel bus is the real constraint, not the DAC. At 165 MSPS the
setup/hold window on the 14 data lines plus clock is tight enough that length
matching and reference-plane continuity matter more than anything else on the
board. I'd keep the whole bus on one layer over unbroken ground, with a return
via at any layer change.
2. Jitter shows up as SFDR. Clock path routing and where the clock source sits
relative to the DAC will set your spurious-free dynamic range at high output
frequencies more than the analog output stage will.
3. Split AVDD/DVDD, but a single ground plane. The 904's output switching dumps
noise back into the digital supply. Local decoupling on separate rails — but I
would not split the ground plane; that usually creates worse return-path
problems than it solves.
4. One question that could simplify the whole layout: are the FPGA pin
assignments fixed, or can they be re-mapped? On the Gowin part the bus pins are
reassignable, and re-ordering them to match the DAC pinout can remove most of
the crossovers — often one fewer layer and a noticeably cleaner board. If the
RTL is already written it's a small change on your side and a large one on mine.
To quote it I'd need the schematic (Altium preferred, but KiCad/OrCAD/PDF are
fine), board outline and mechanical constraints, target layer count if you have
one, connector and mounting requirements, and whether you want fab/assembly
files or just the layout database.
How I work: fixed price quoted up front with the assumptions written out, so
you can see what's driving the number. No hourly meter. Payment split across
milestones, and progress you can look at rather than silence until delivery.
US-based entity to contract with; happy to sign an NDA before you send anything.
Reply here and I'll follow up — I can have a fixed price and schedule back to
you within a day.
Home
Help
Search
Login
Register
