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 89

2026-11-05 02:46 PST (2026-11-05T10:46:11Z UTC) · commit 74a2044 (74a20445741559bb4ddbeee2009f2bcce97e1be7)

ADOPTED

heal_big batch 2 (exp40 -> exp41, checkpointed; GND tail stopped by hand after 27 connections when its 1-item subgroups proved to be item-model noise under the zone-defined audit): CMP_QN and FLY_PRI completed, +3V3A 3 -> 2 groups, APD_K 9 -> 5 (RJ2.2 group, R31.1, D1.5, R47.2 remain), GND item-subgroups merged without moving its audit count (zone fills define it). Refused again, all in ~0-7 s (sealed first millimetre): U4.12, U11.10-12, U11.13, U7.4, U14.6, U5.3, J1.B5, U4.5, U4.27, C15.2, U7.7. Audit: nets 31 -> 29, violations 75. Next: escape-fan census over the sealed pads, hand escapes into open field, then heal/thread take the lengthened stubs.

Nets fully routednot recorded
Pins failednot recorded
Clearance violations75
Unconnected nets29
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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