docs: correct stale 'part fields blank' notes + flag kicad-cli zone-refill DRC trap

All eFuse/RExt/EE-CS parts (U13, R43-R47, C66, R44, D13) are picked with
MPN+LCSC in the live BOM and placed+routed on the PCB - the TODO/REVIEW
notes calling their fields 'intentionally blank' were written when the
parts were first added and never updated. Corrected to reflect the
committed state.

Also documents the kicad-cli DRC gotcha that caused a false alarm: it
does not refill zones, so it reports phantom GND-via-in-3V3-pour and
thermal-pad clearance errors (actual 0.000mm) on a board the GUI reports
clean. Added a warning at the top of TODO and in REVIEW section 7 so no
future session mistakes it for a real defect.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
2026-08-02 08:37:39 +00:00
parent 7d7ab34bff
commit a72e4ab1d4
2 changed files with 62 additions and 42 deletions
+45 -35
View File
@@ -1,5 +1,16 @@
# re-bba-rb board — open items from hardware review (2026-07-17)
> **Status 2026-08-02:** board is **DRC-clean in the KiCad GUI and all BOM
> parts are picked** (eFuse U13 + R43R47/C66, RExt R44, EE_CS R43, D13, all
> verified present with MPN+LCSC in the live schematic/PCB). ⚠️ **Do not trust
> `kicad-cli pcb drc` blindly** — it does not refill zones and will report
> phantom GND-via-in-3V3-pour / thermal-pad clearance "errors" (actual 0.000 mm)
> that the GUI resolves on refill. See REVIEW.md §7. The per-session DRC counts
> quoted lower in this file predate the 2026-07-31 eFuse work; the GUI is the
> authority and it is clean. Remaining work is bench/verification + JLC
> order-form options, not schematic/PCB defects.
Full review of schematics + PCB against component datasheets (in
`datasheets/`), the WIZnet W5100S reference schematic, and JLCPCB
manufacturing limits. Status 2026-07-18: **all three critical findings fixed
@@ -40,15 +51,16 @@ Major work this session:
driven directly by the FPGA's `SB_RGBA_DRV` hard macro, no series resistor)
need no resistor change — flagged as slightly reduced current-source
headroom at the higher Vf, not fixed (nothing to fix, no resistor exists).
- [ ] **D13 (yellow, Everlight C72038) and the 10 kΩ 0402 resistor
(UNI-ROYAL C25744, used by 12 designators) are ALSO reported out of
stock** — real in-stock alternatives were being researched
(candidates: Hubei KENTO KT-0603Y/KT-0805Y for D13; YAGEO
RC0402FR-0710KL C60490 or Vishay CRCW040210K0FKED C71617 for the
10k) but never confirmed/committed — stock claims from web search
proved unreliable earlier this session (contradicted by direct
JLCPCB part-page checks twice), so these need a live stock check
before ordering, same as the green LED did.
- [x] **D13 and the 10 kΩ resistor — COMMITTED in the live BOM**
(verified 2026-08-02): D13 = Hubei KENTO **KT-0603Y (C2287)**; the
10 kΩ 0402 = UNI-ROYAL 0402WGF1002TCE **C25744** (R43 and others).
These are the chosen parts, no longer unresolved.
- [ ] Standard order-time step (not a blocker, applies to the whole
BOM): do a **live JLCPCB stock check** just before ordering —
earlier web-search stock claims proved unreliable, so trust
only the JLCPCB part page at order time. C2287 and C25744 were
the out-of-stock scares that prompted this note; re-confirm them
specifically.
- **J5 added**: a second SP1 gold-finger connector, footprint copied from
the eth2sp1 open-source project (github.com/jochemvdmeulen/eth2sp1),
library file `hardware/SP1_eth2sp1_reference.kicad_mod`. Real purpose:
@@ -212,19 +224,19 @@ Major work this session:
(caps inrush, 3.8× the ~130 mA steady-state load); R46/R47 620 k/100 k
set UVLO ≈ 8.9 V; C66 100 nF is Cin. U13 = TPS25961DRVR, **LCSC
C5571272**.
- [ ] **PCB: place + route U13, R45, R46, R47, C66.** Two datasheet
requirements to honour in layout: (1) the **thermal pad must
connect to the GND plane** — the footprint is the `_ThermalVias`
variant, confirm the vias actually reach In1/In2 GND; (2) **OVLO
absolute max is 6.5 V** and it is tied to GND for the internal
fixed threshold — that connection must be solid and must never
see 12 V. Keep C66 close to U13's IN pin.
- [ ] **Select parts for R45 (100 k), R46 (620 k), R47 (100 k), C66
(100 nF)** — fields intentionally left blank. R45/R47 can reuse
the UNI-ROYAL 100 k C25741 already used by R4 (NOT C60490 - that part
is 10 k, an earlier note in this file had it wrong).
**Do not round R45 into 58.866.7 kΩ, 111142 kΩ or 250500 kΩ**
(datasheet Table 7-1 forbidden ON-resistance bins).
- [x] **PCB: U13, R45, R46, R47, C66 placed + routed** (verified on disk
2026-08-02: U13 at 206.99,48.47 with R45/R46/R47/C66 clustered
around it; 0 unconnected items board-wide). Two datasheet
requirements honoured in layout: (1) the **thermal pad connects to
the GND plane** — footprint is the `_ThermalVias` variant; (2)
**OVLO absolute max 6.5 V** tied to GND for the internal fixed
threshold. Keep this arrangement.
- [x] **Parts for R45/R46/R47/C66 — PICKED** (verified in live BOM
2026-08-02): R45/R47 = UNI-ROYAL 100 k **C25741**, R46 = YAGEO
620 k RC0402FR-07620KL **C137952**, C66 = 100 nF **C1525**.
R45 = 100 k is clear of the forbidden ON-resistance bins
(58.866.7 kΩ, 111142 kΩ, 250500 kΩ) — do not "round" it into
them if ever re-selected.
- [ ] **Bench: verify inrush at GC power-on** — expect ≈500 mA for
~2.9 ms (was ~621 mA slew-limited, unbounded before the eFuse).
Also confirm no retry/motorboating at startup; if the rail sags
@@ -381,19 +393,17 @@ Major work this session:
separates chassis via 1 nF/2 kV — acceptable choice, confirm intent).
- [ ] Confirm at bring-up (from CLAUDE.md): W5100S register addresses / MR
bits were written from memory.
- [ ] **Measure Y2 crystal drive level at bring-up and tune R44 (RExt).**
Added 2026-07-31 at **49.9 Ω** (gain margin 7.53×, DS requires ≥5;
**ceiling 100 Ω**, 120 Ω fails startup). Reason it exists: the fitted
crystal is rated **DL = 200 µW max** but W5100S Table 9 says select a
**500 µW** part, so the chip can overdrive it ~2.5×. Part fields are
deliberately blank — confirm the value on the bench (scope the crystal,
compute DL) before committing a BOM line. If drive is comfortably under
200 µW a smaller value (or 0 Ω, per the WIZnet reference) is fine; if
it's high, go up but stay ≤100 Ω. See REVIEW.md §5.
- [ ] **Select a part for R43** (EE_CS 10 kΩ pull-down, added 2026-07-31).
Any 10 kΩ 0402 works — the in-stock YAGEO RC0402FR-0710KL / C60490
already used on R2/R5/R18/R31/R36 is the obvious choice; fields were
left blank so it doesn't silently inherit an out-of-stock part.
- [ ] **Measure Y2 crystal drive level at bring-up and tune R44 (RExt) if
needed.** Fitted at **49.9 Ω** (part PICKED: UNI-ROYAL 0402WGF4999TCE
**C25120**, verified in live BOM 2026-08-02). Gain margin 7.53× (DS
requires ≥5; **ceiling 100 Ω**, 120 Ω fails startup). Reason it exists:
the fitted crystal is rated **DL = 200 µW max** but W5100S Table 9 says
select a **500 µW** part, so the chip can overdrive it ~2.5×. Only a
bench action remains: scope the crystal, compute DL; if comfortably under
200 µW a smaller value (or 0 Ω per the WIZnet reference) is fine, if high
go up but stay ≤100 Ω. See REVIEW.md §5.
- [x] **R43 part PICKED** (EE_CS 10 kΩ pull-down): UNI-ROYAL 0402WGF1002TCE
**C25744** (verified in live BOM 2026-08-02). No action remains.
## JLCPCB ordering notes (DRC clean — these are order-form options)