Attachment Review
see the mechanical specification and pin config
Image
Thought for 10 sec
Yes — I see it: the SKA60 uses a non-uniform 8-pin bottom-view pattern, not a simple 5.08mm grid. I’ll check the current U1 footprint against those coordinates and record/fix the footprint risk.
Worked for 5 mins 40 sec
Updated U1 to match the attached SKA60 mechanical spec: the footprint now uses the non-uniform bottom-view 8-pin pattern and 1.3mm drilled / 2.2mm pads for the 1.0mm pins.
Open items:
- The published custom part may still need the same footprint correction; I applied overrides in this project layout.
- DRC still reports airwires because routing has not been done yet.
Documented here: PCB Layout Notes.
Fix part, route, review
Fix custom part
Route the board
Run full DRC
Explain pin pattern
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Ask about this doc
Schematic Design Notes
Current Schematic Status
- Main schematic capture is complete for the requested power-distribution architecture.
- Electrical checks currently show no open schematic ERC warnings/errors for floating pins, no-connects, pin-to-pin conflicts, power pins, single-pin nets, or undriven nets.
- PCB DRC airwire/overlap errors are expected at this stage because no PCB placement/routing has been performed yet.
Implemented Blocks
- J1: 24V DC input, Phoenix Contact 1803277 / MC 1,5/ 2-G-3,81, 3.81mm pitch, right-angle pluggable header.
- F1: 5x20mm PCB fuse holder for a 4A slow-blow cartridge fuse.
- F2: RUEF200 30V-class 2A-hold PTC for the 24V pass-through output branch.
- J2: protected 24V output terminal block.
- U1: Mean Well SKA60B-12 24V input to 12V/5A isolated DC-DC module.
- F3/F4: Littelfuse 16R160B radial PTCs for 12V OUT 1 and OUT 2.
- F5: Littelfuse 16R185B radial PTC for 12V OUT 3.
- J3/J4/J5: protected 12V output terminal blocks.
- C1: 1uF/50V ceramic across 24V input near U1.
- C2: 100uF/25V electrolytic across the 12V rail near U1.
- C3: 1uF/25V ceramic across the 12V rail near U1.
- D1/R1: 24V green indicator LED with 2.2kΩ, 0.5W resistor.
- D2/R2: 12V green indicator LED with 1kΩ resistor.
- MH1-MH4: 3.2mm non-copper NPTH mounting holes for M3 screws.
Net Assignments
Table
| Net | Function | Current Class |
|---|---|---|
| 24V_IN_RAW | J1 positive input before fuse | 5A board-copper target |
| 24V_FUSED | Fused 24V bus after F1 feeding U1, F2, C1, and D1/R1 | 4A fuse-limited nominal |
| 24V_OUT | F2-protected 24V output to J2 | 2A branch |
| 12V | U1 output rail feeding C2/C3, D2/R2, and F3/F4/F5 | 5A max |
| 12V_OUT1 | F3-protected 12V output to J3 | 1.6A nominal PTC hold |
| 12V_OUT2 | F4-protected 12V output to J4 | 1.6A nominal PTC hold |
| 12V_OUT3 | F5-protected 12V output to J5 | 1.85A nominal PTC hold |
| GND | Common negative; input and output negatives intentionally tied | 5A return target |
Datasheet-Backed Custom Parts Created
- SKA60B-12: /beedo/ska60b-12
- 16R160B: /beedo/16r160b
- 16R185B: /beedo/16r185b
- RUEF200: /beedo/ruef200
Engineering Notes and Risks
- A 16V PTC is not suitable on the 24V pass-through branch, so the 24V branch uses a 30V-class RUEF200 instead.
- The 16R160B and 16R185B 12V branch PTCs have room-temperature hold-current ratings. Their hold current must be derated for 60°C enclosed ambient.
- The third 12V branch uses 16R185B because the exact Littelfuse USBR 2.0A radial 16V value was not available in the sourced USBR table. If true 2.0A continuous hold at 60°C is required, the part should be revisited.
- The 4A slow-blow input fuse may be marginal if the SKA60B-12 is near 60W output and the 24V pass-through branch is loaded simultaneously, especially near the module's 18V minimum input where converter input current rises.
- The SKA60B-12 output capacitance is 100uF + 1uF locally, below the stated 220uF external capacitance limit. Downstream load capacitance should also be considered.
- No reverse-polarity protection or TVS/transient clamp has been added yet; field wiring and long 24V leads may justify adding these before layout release.
- Common negative is intentional and defeats downstream isolation benefits of the SKA60B-12.
- Layout must use pours/wide copper, avoid narrow neck-downs around connectors/fuse/PTCs, and keep PTCs thermally separated from U1.
- Current DRC airwire/overlap findings are expected until placement and routing are performed.
Current Schematic Status
Implemented Blocks
Net Assignments
Datasheet-Backed Custom Parts Created
Engineering Notes and Risks
