USB Sensor Node
Worked for 7 mins 40 sec
Placement is complete: USB/power is grouped on the left/lower-left, DDS and low-level analog are central, and the output amplifier sits behind the right-edge BNC. I’m checking and tightening any remaining decoupling-placement issues now.
Worked for 15 mins 19 sec
Created a project doc
PCB Layout Review — Programmable Function Generator
Board outline set to 100 mm × 80 mm with 2 mm rounded corners. Stackup set to 4 copper layers for USB, SPI, analog output, and multi-rail po...
View docPCB layout placement is complete on a 100 × 80 mm, 4-layer board: USB/power is on the left, LT3471 power is lower-left, DDS/control/conditioning are central, and the THS3091/BNC output is on the right. I ran placement, DRC, and BOM checks; details are captured in PCB Layout Review.
Open items:
- Board is not routed yet, so airwires are expected.
- DRC still reports exposed-pad footprint copper overlap on U3, U6, and U10.
- Generic resistors/capacitors/inductors still need final orderable MPNs for assembly.
Suggested next steps:
- Repair or replace U3/U6/U10 exposed-pad footprints.
- Assign real MPNs/packages to generic passives and inductors.
- Route the PCB, then re-run full DRC.
Fix footprints and BOM
Fix footprint overlaps
Assign passive MPNs
Route the PCB
Run full checks
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PCB Layout Review — Programmable Function Generator
Layout Work Completed
- Board outline set to 100 mm × 80 mm with 2 mm rounded corners.
- Stackup set to 4 copper layers for USB, SPI, analog output, and multi-rail power routing.
- All 90 physical components placed on the top side.
- Functional placement zones:
- Left edge: USB-C input J1, USB ESD and CC resistors, input protection U1.
- Upper-left: STM32 U4, SWD header J3, USB routing passives.
- Lower-left: LT3471 ±15 V switching supply, inductors, Schottky diodes, output capacitors, and feedback/soft-start passives.
- Center: AD9833 DDS U5, 25 MHz oscillator X1, reconstruction/filtering and waveform mux U6.
- Center-right: ADA4898 conditioner U10, DAC/digipot control U9/U7.
- Right edge: THS3091 output amplifier U8 and BNC output J2.
Placement Status
- No component body overlap or outside-board placement errors remain.
- Routing congestion improved after spreading the central control/analog section; current layout summary reports routing space is acceptable on the 4-layer stackup.
- All components remain top-side for simpler assembly.
DRC / Layout Checks
Table
| Check Area | Result | Notes |
|---|---|---|
| Board size / placement | Pass | Components fit on 100 × 80 mm board |
| Stackup | Pass | 4-layer stackup confirmed after final board update |
| Component overlap / outside board | Pass | No reported component placement errors in final checked set |
| Airwires | Expected open | Board is placed but not routed; airwires remain until routing phase |
| Overlapping copper | Open issue | 12 errors on U3, U6, and U10 exposed-pad/thermal-mount footprint geometry |
| Missing footprints | Pass | No missing-footprint errors reported |
| BOM availability | Mixed | Main ICs/connectors have MPNs; generic passives/inductors still need final orderable MPNs |
Open DRC Issue: Exposed-Pad Footprint Copper
The overlapping-copper checks are concentrated on:
- U3 LT3471EDD#PBF exposed GND pad area
- U6 ADG758CPZ exposed/substrate VSS pad area
- U10 ADA4898-2YRDZ exposed pad area
The checks appear to be caused by unnamed duplicate footprint thermal/mount pads overlapping the named exposed pad terminals. Attempting to delete the duplicate internal mount pads by UID did not succeed because those nodes are not exposed as normal editable layout nodes. This should be resolved before manufacturing by replacing/repairing those footprints or using a library footprint variant with a single correctly-netted exposed pad.
BOM Check Notes
- 17 non-generic part groups have MPNs populated.
- Generic passives/inductors are still generic and trigger manufacturer-part-number checks:
- 33 resistors
- 37 capacitors
- 3 inductors
- Before assembly export, select real MPNs/packages for the generic passives, especially:
- LT3471 inductors L1/L2/L3 with adequate saturation current
- ±15 V rail capacitors C23/C24/C25 and output amp decoupling C34-C37
- precision feedback/gain resistors R20-R27/R30-R33
Recommended Next Steps
- Resolve U3/U6/U10 exposed-pad footprint overlap issue.
- Assign package and MPNs to generic passives and power inductors.
- Route the board, starting with power rails and high-speed/analog-sensitive nets.
- Re-run full DRC including airwires after routing.
Layout Work Completed
Placement Status
DRC / Layout Checks
Open DRC Issue: Exposed-Pad Footprint Copper
BOM Check Notes
Recommended Next Steps
