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 113

2026-11-05 11:51 PST (2026-11-05T19:51:10Z UTC) · commit 258c23d (258c23d8cf8d97b89413338b96d384f25ddd3509)

ADOPTED

U7 west-column escapes + residue stubs harvested. Ripped the CAP_CLK/ULPI_NXT F palisade (x=71.88/72.62 verticals + 2 NXT diagonal steps – via-proof pair, 0.74 apart vs 0.625 needed each side; pad row equally sealed at 0.25 gaps) and laid the four row lanes west on F: +3V3A U7.6 CONNECTED via its lane + heal to the (74.12,10.38) staircase; +5V U7.4, DP_PHY U7.7, DM_PHY U7.8 lanes placed as open-field anchors (heals refused the 55-65mm D3 hauls and the +5V main-group haul – Class B long-haul residue, anchors in place). Palisade repaid: heal rejoined ULPI_NXT (13 items, 0 vias) and CAP_CLK’s split (44 items). bridge (exp99, pre-pass) had connected +3V3A U7.16 (gap 1.99) but ripped 2 victims: ULPI_D7 (rejoined by heal) and ULPI_CK’s F->In2 junction via at (77.62,17.88) (restored by hw/fix_ckvia.py, site shape-tested clean). Also in the chain: hand_stub escapes on exp95 for HV_EN/HV_SHDN/VCAP2/PHY_1V8A/RBIAS/XI and hand_via vias for CDR_SQUELCH/SWDIO (anchors for the heal campaign); fix_escape placed a +3V3A U7.16 via (redundant with bridge’s join). XO U7.27 named sealed: DATP via (76.88,10.62) + XI stub + PHY_1V8 pad fence every exit – north-row rework residue. heal/heal_big/thread_far went 0-for on the stubbed singles (grid anchor wall + 15mm pair gate) – the lane/via hand escapes are the working vehicle for this family.

Nets fully routednot recorded
Pins failednot recorded
Clearance violations87
Unconnected nets31
Audit verdictFAIL

Routes — all copper layers and each layer

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

Top

Pass 113 — top

Bottom

Pass 113 — bottom

← Pass 112 · all passes · Pass 114 →