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 142

2026-11-05 23:07 PST (2026-11-06T07:07:47Z UTC) · commit 1dad870 (1dad870609ad65574b0d373f52fd2519f01508c1)

ADOPTED

Shorts singles cleared: shorting_items 6 -> 0 (class closed). Five micro-localities, each rip+heal with DRC checks between: ULPI_NXT x C17.1/VCAP1 (ripped 13 segs in (69.8,4)-(71.8,12.5); heal reconnected 4 groups – NXT was more fragmented than it looked); CMP_IN x R11.1/TEST_IN (ripped 4 in (36.5,39.5)-(41.5,44.5); reconnected); HV_SHDN x R25.1/+5V (ripped 8 in (3.5,-22.5)-(10,-16.5); 3 groups reconnected; U6.42 group STILL isolated, pre-existing residue); +VA x D2.2/APD_K_ALT (ripped 10 in (22,58.5)-(27,64); reconnected 59+1 items); ILIM_P x C41.2/GND (cleared ILIM_P’s 14 items in (41,58)-(44.5,61.5) including the via on C41.2; heal re-laid the 19-item group). KiCad DRC referee, exp171 -> exp172: violations 283 -> 278, shorting_items 6 -> 0, clearance 37 -> 34, solder_mask_bridge 12 -> 7, unconnected items 45 UNCHANGED, copper_edge_clearance 88 unchanged, track_dangling 23 -> 27 (fresh heal stubs, prune next).

Nets fully routednot recorded
Pins failednot recorded
Clearance violations68
Unconnected nets31
Audit verdictFAIL

Routes — all copper layers and each layer

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

Top

Pass 142 — top

Bottom

Pass 142 — bottom

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