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 111

2026-11-05 09:52 PST (2026-11-05T17:52:47Z UTC) · commit 4331784 (433178454c7120888ef1d984eaafdf4de9f3b421)

ADOPTED

SET_P connected: U13 relocated + re-heal of its 6 nets (hw/move_u13.py, heal_nets, hw/fix_u13_6.py). The decided (-4,0) west move is REFUTED on the current field (exact pad check): destination lands in the routed NEG_RAW staircase web (EP vs 18 tracks, ILIM_P/+5V pins vs more, need 0.25). Full-ring placement search (dx -8..+2, dy -7..+7) found one clean cluster SW; executed (-6.75,-7.00) -> U13 at (41.25,55.00), pin 7 0.47 mm from the SET_P web. One SET_P web vertex (via 43.875,61.375 + 2 segments) ripped pre-move; heal re-bridged it. heal joined SET_P/+VA/ILIM_P and +5V pins 1/2/3; U13.6 (+5V) refused twice more (stubbed and unstubbed) and the pure-F west bridge was refused on the GND/DM_PHY/ILIM_P braid – landed as a one-via B.Cu hop: via (42.68,56.28) overlapping the pad, B run NW into the +5V B staircase at (41.75,53.25). DELTAS vs pass 110: nets 32->31 (SET_P joined, +5V back to its 4 pre-existing groups), violations 87->87 (census byte-identical, +0 new).

Nets fully routednot recorded
Pins failednot recorded
Clearance violations87
Unconnected nets31
Audit verdictFAIL

Routes — all copper layers and each layer

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

Top

Pass 111 — top

Bottom

Pass 111 — bottom

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