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 8

2026-11-04 00:21 PST (2026-11-04T08:21:31Z UTC) · commit f2b2fbe (f2b2fbebc1693e7055479a407f3cbc098f60b14d)

NOT ADOPTED

Bundled change — two strategy changes in a single commit, the practice this counter replaces: diagonal moves added to the repair router AND the repair re-run over the pass-7 board. Result: 0 groups connected, no progress, not adopted. The commit’s real payload is the per-pin diagnosis of the residue (results/diagnose-repaired6b.txt): of 99 isolated groups, 50 NO_EXIT, 16 POCKET, 20 WIDE_NO_GOAL, 13 REACHES — pads boxed in by placement, which is what pass 9 changes.

Nets fully routednot recorded
Pins failednot recorded
Clearance violationsnot recorded
Unconnected netsnot recorded
Audit verdictnot recorded

Routes — all copper layers and each layer

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

Top

Pass 8 — top

Bottom

Pass 8 — bottom

Board saved as hw/pdlvds_rx.repaired6b.kicad_pcb (1,587 tracks per results/repair6-attempt2.log). No audit was committed for this pass, so unconnected nets and clearance violations are not recorded. No renders were committed. Renders backfilled on 2026-11-04 by rendering the board file as of this pass's commit; not contemporaneous with the pass. Composite render backfilled on 2026-11-04 by rendering the board file as of this pass's commit; not contemporaneous with the pass.

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