PDLVDS-RX — photodiode LVDS receiver

Clean-room receiver for the Miniscope Zero optical uplink: Excelitas C30737LH Si APD → OPA657 TIA → LMH7220 comparator (LVDS out, DAC-set threshold) → ADN2813 CDR → STM32H723 + USB3300 USB-HS. Design target: 50 Mbps line rate, 8b/10b (40 Mbps payload); the paper's mode: 8 Mbps Manchester (16 Mbaud), as transmitted. LT3757 flyback APD bias 150–420 V. USB-C powered; verify on any laptop over USB, no FPGA attached.

Pass 138

2026-11-05 22:10 PST (2026-11-06T06:10:10Z UTC) · commit 0a9e214 (0a9e214298170b578f1715b359a6e39265b91378)

ADOPTED

Shorts locality C: HV_EN x C4 GND (7 items). Ripped 14 HV_EN segments intersecting the C4 pad box (x 24..27.5, y 13.8..17.5) – the B.Cu diagonal grazed the C4.2 PTH ring at its corner – and re-laid with heal_nets (scratch/heal8): main 68-item group reconnected around the pad in 11 s. HV_EN’s U6.97 pad group remains STILL isolated (pre-existing, residue-family queue; the rip box is nowhere near U6). KiCad DRC referee, exp164 -> exp165: violations 338 -> 320, shorting_items 34 -> 27 (zero HV_EN shorts remain), solder_mask_bridge 38 -> 31, unconnected items 48 UNCHANGED, clearance 44 unchanged, track_dangling 20 -> 21 (one fresh heal stub, prune food).

Nets fully routednot recorded
Pins failednot recorded
Clearance violations105
Unconnected nets34
Audit verdictFAIL

Routes — all copper layers and each layer

All layers
All layers — click the image to open the full-size SVG in a new tab.
All layersAll layers F.Cu layerF.CuIn1.Cu layerIn1.CuIn2.Cu layerIn2.CuB.Cu layerB.Cu

F.Cu In1.Cu In2.Cu B.Cu

Top

Pass 138 — top

Bottom

Pass 138 — bottom

← Pass 137 · all passes · Pass 139 →