LR P3A
About the LR P3A PCB
LR P3A is an open source PCB design by Lightiam, published on GitHub under the BSD-3-Clause license. It is a 16-layer board measuring 167 × 111.2 mm, with 44 components from 38 distinct parts.
Other key parts include the U1, U2, U3, U4 and U5. By type, the board carries 20 capacitors, 10 ICs and 5 connectors.
From the project
ASIC-NCE
This folder ingests the owner-supplied LightRail AI Gen3 NCE Datasheet Rev 3.0 (LightRailGen3NCEDatasheetRev3.0.pdf, "Production Release for Seeed Studio Fusion PCBA") as the authoritative electrical design source — the thing the repo had been missing.
Start here: DATASHEETRECONCILIATIONANDBUILDPLAN.md.
The datasheet describes a real, buildable board (LR-P3A Rev 6.3) with complete real data — and it is a different board than the repo's TFLNAINODEX2. Critically, it places the NCE ASIC + HBM stacks inside the co-packaged (CPO) module on a silicon interposer, so the board-level NCE/HBM…
Main components on the LR P3A
LR P3A bill of materials (BOM)
44 components, 38 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | U1 | U1 | |
| 1 | U2 | U2 | |
| 1 | U3 | U3 | |
| 1 | U4 | U4 | |
| 1 | U5 | U5 | |
| 1 | U6 | U6 | |
| 1 | U7 | U7 | |
| 1 | U8 | U8 | |
| 1 | U9 | U9 | |
| 1 | U10 | U10 | |
| 1 | J1 | J1 | |
| 1 | J4 | J4 | |
| 1 | J5 | J5 | |
| 1 | J6 | J6 | |
| 1 | J7 | J7 | |
| 4 | — | BH1, BH2, BH3, BH4 | |
| 4 | — | MH1, MH2, MH3, MH4 | |
| 1 | U_LDO_0V9 | U_LDO_0V9 | |
| 1 | C1 | C1 | |
| 1 | C2 | C2 |
Show 18 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | C3 | C3 | |
| 1 | C4 | C4 | |
| 1 | C5 | C5 | |
| 1 | C6 | C6 | |
| 1 | C7 | C7 | |
| 1 | C8 | C8 | |
| 1 | C9 | C9 | |
| 1 | C10 | C10 | |
| 1 | C11 | C11 | |
| 1 | C12 | C12 | |
| 1 | C13 | C13 | |
| 1 | C14 | C14 | |
| 1 | C15 | C15 | |
| 1 | C16 | C16 | |
| 1 | C17 | C17 | |
| 1 | C18 | C18 | |
| 1 | C19 | C19 | |
| 1 | C20 | C20 |
LR P3A design files
The KiCad project lives in the Lightiam/Fab07 repository on GitHub; these links point at the commit this page was built from.
LR P3A: common questions
How big is the LR P3A PCB?
The LR P3A measures 167 × 111.2 mm, has 16 copper layers and is 1.6 mm thick.
How many components are on the LR P3A?
44 components, from 38 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the LR P3A design files?
From the Lightiam/Fab07 repository on GitHub, which has the KiCad layout and the BOM; the links under Design files point to each one.
Can I use the LR P3A design in my own project?
Yes, under the terms of its BSD-3-Clause license, which Lightiam chose for the repository.
