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 86

2026-11-05 01:20 PST (2026-11-05T09:20:20Z UTC) · commit 6d73c4c (6d73c4c7f0bf913502fbd082de3ac4da2c19c7de)

ADOPTED

heal_big (15M cap) on exp37 -> exp38: +3V3D_CDR’s U4.1 group merged (42 items, 2 vias); +5V 7 -> 5 groups (T1.1 group and the (26.42,-18.54) island connected). Refused in ~5 s each despite the diagnosis BFS reaching the goal halo (cost-model refusal, the Class B signature): U4.12, U11.10-12 cluster, U11.13, U7.4, U14.6 – these go to thread/hand work, not a third engine attempt. Audit: nets 35, violations 67 (group counts fell; net count unchanged). NOTE: two VM replacements hit during this stretch (diagnose run SIGTERM’d at 805 s, toolchain restored from cache twice); committed work unaffected.

Nets fully routednot recorded
Pins failednot recorded
Clearance violations67
Unconnected nets35
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

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Pass 86 — top

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