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 122

2026-11-05 15:23 PST (2026-11-05T23:23:24Z UTC) · commit eadd3bc (eadd3bcfdf4c36ea14547ffdc3e5d4e6156d677d)

ADOPTED

XI/XO (queue item 5) stand as NAMED RESIDUALS; XI fanout ray placed as the heal-enabler attempt. XO: U7.27 SEALED – hand_stub refuses all 16 directions; every via site tiled by the CDR_DATP via (76.88,10.62) at 0.03-0.155mm, ULPI_CK’s wall and U7.26 PHY_1V8’s pad; the only mechanisms are the coordinated CDR-pair relay or a U7 move (both parked with the ULPI knot). XI: heal refused before AND after this ray (pad-cell seal in the grid model), thread_far refused (gap 8.45, no thread); remaining mechanisms are the west-corridor hand-route (crosses +3V3A’s 0.60 west trunk + the GND field at y19-22, multi-via marginal windows) or the pair relay. This pass places ONLY the XI ray: nub extended (76.25,11.03)->(76.25,10.55) + west bend ->(75.85,10.55), exact-tested clean; no via fits at the ray (CDR_DATP buried staircases). DELTAS vs pass 121: nets 27->27, violations 71->71 expected (audit verifies), XI groups unchanged 2. No victims. NEXT: queue item 6 (east-column +3V3D_CDR + CDR_LOL), then the residue family.

Nets fully routednot recorded
Pins failednot recorded
Clearance violations71
Unconnected nets27
Audit verdictFAIL

Routes — all copper layers and each layer

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

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