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 67

2026-11-04 15:56 PST (2026-11-04T23:56:47Z UTC) · commit bf7487d (bf7487d18ea474483a8c126247bf264d02f05171)

ADOPTED

expansion routing 2: bridge campaign (4 rounds, hw/bridge.py batched) on the repairg exp1 checkpoint board. Total groups 253 -> 226, unconnected nets 69 -> 65, violations 2 (justified D1 pair). Round yields -16/-6/-3/-2: nearest-pair bridges consumed; rails merged one pair per round (+3V3D/+5V/+3V3A/+3V3D_CDR all connected once per round), HV cluster nets bridged in the strip (HV_FBX, HV_SHDN, HV_RAW, HV_SENSE, FLY_PRI, HV_SEC, HV_VC2), +/-VA joined. ULPI bus (U7<->U6) untouched: nearest fragments >3 mm apart (bridge gap sentinel 9.9) — A* territory. Decay curve says change shape: next = rails bridge-chain, thread.py on geometry-stuck pairs, repairg2 sweep for long hauls.

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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Bottom

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bridge rounds in results/bridge-r1..r4.log; audits in results/audit-bridge-r1..r4.txt

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