USB Sensor Node


Board is now set to a 100 × 80 mm, 4-layer stackup with internal GND and power planes. I’m placing the functional blocks next, keeping switching power away from the low-level DDS/analog path.
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.
Created a project doc

PCB Layout Review — Programmable Function Generator

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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...
PCB 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:
  1. Repair or replace U3/U6/U10 exposed-pad footprints.
  2. Assign real MPNs/packages to generic passives and inductors.
  3. Route the PCB, then re-run full DRC.
Fix footprints and BOM
Fix footprint overlaps
Assign passive MPNs
Route the PCB
Run full checks

X1 OUT - U5 MCLK
U4 PA5 - U5 SCLK
U5 VDD - C7 P1
U4 PA7 - U5 SDATA
U5 CAP/2.5V - C9 P1
U5 VDD - C7 P1
U5 COMP - C10 P1
U5 VDD - C7 P1
U5 VOUT - R17 P1
U4 PA4 - U5 ~FSYNC
U5 AGND - C7 P2
U5

Programmable Function Generator

Programmable Function Generator thumbnail