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:
+45
-35
@@ -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 + R43–R47/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 58.8–66.7 kΩ, 111–142 kΩ or 250–500 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
|
||||
(58.8–66.7 kΩ, 111–142 kΩ, 250–500 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)
|
||||
|
||||
|
||||
Reference in New Issue
Block a user