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 69

2026-11-04 16:29 PST (2026-11-05T00:29:35Z UTC) · commit 810cb02 (810cb02d823fc1c4b4da12994056a97a1967105c)

ADOPTED

heal_nets rails phase (hw/heal_nets.py, repairg engine under a named net list): +3V3D/+5V/+3V3A/+3V3D_CDR. 48 groups connected in 536 s, EVERY merge audit-real: total groups 225 -> 177, nets 65, violations 2. +3V3D 38 -> 7, +5V 23 -> 10, +3V3A 9 -> 5, +3V3D_CDR 7 -> 7 (zero merges — U4’s rail pins are walled; rip-priced threading next). 25 groups STILL isolated, failing fast (1-12 s): U5 power pins x4, X2.1/X2.4 group, FB1.1, R25.1, U7.4 et al. — named residue for thread.py (rip pricing) after the signal phase.

Nets fully routednot recorded
Pins failednot recorded
Clearance violations2
Unconnected nets65
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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heal log: results/heal-rails.log; audit: results/audit-exp4.txt

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