PCB Design for Hothouse Project
Thought for 5 sec
You usually don’t need to know “old” by age. In this case, “old traces” means any routed copper trace that is currently causing errors after we resized/replaced the board.
Easiest way to identify them:
- Open the Review / Issues panel.
- Look for these issue types:
- Dangling Traces
- Floating Copper
- Overlapping Copper
- Airwires
- Click one issue, for example
Trace 147borTrace 321b. - Flux should highlight that trace on the PCB.
- That highlighted trace is one of the problem traces to unlock/delete.
- Repeat for each listed trace issue.
Do not delete:
- component footprints
- pads
- board outline
- schematic parts
- net labels
Do delete/unlock:
- highlighted copper routes/traces/vias associated with those review errors.
A shortcut: if there’s an option like delete all routing, rip up traces, or clear routed copper, use that. That is safer than trying to identify individual old traces one by one, because the schematic connections remain intact and the board will simply show airwires again for rerouting.
List trace issues
Rip-up guidance
Check USB2_D_P
Highlight DRC issues
Refine this doc
Ask about this doc
Power/Interconnect PCB Design Notes
Implemented Schematic Scope
This project now contains the Hothouse power/interconnect PCB schematic block. It includes:
- 9 V DC barrel input connector
- 500 mA resettable PTC fuse
- Series Schottky reverse-polarity diode
- AP63205WU-7 fixed 5 V buck regulator
- AP63205 datasheet-recommended support parts:
- 10 uF input capacitor
- 4.7 uH buck inductor
- 2 x 22 uF output capacitors
- 100 nF bootstrap capacitor from BST to SW
- 470 uF shared 5 V bulk capacitor
- 3 x 5 V/GND JST-PH power outputs for the three unit PCBs
- 8 x JST-PH audio chain connectors for Unit 1 OUT -> Unit 2 IN and Unit 2 OUT -> Unit 3 IN
- 4 x 4.7 uF audio DC-blocking capacitors for the internal stereo chain
- 3 x USB Micro-B panel receptacles and 3 x 5-pin internal USB extension headers
- Chassis coupling network: 1 Mohm resistor and 10 nF capacitor from PCB GND to chassis
Buck Regulator Selection
Selected regulator: AP63205WU-7 by Diodes Incorporated.
Datasheet facts used:
- Input range: 3.8 V to 32 V
- Output current: 2 A continuous
- Fixed output option: 5.0 V for AP63205
- Absolute maximum VIN: -0.3 V to +35 V DC
- Recommended 5 V external components: 4.7 uH inductor, 10 uF input capacitor, 2 x 22 uF output capacitors, 100 nF bootstrap capacitor
Power Budget
Estimated downstream load:
- 3 x Daisy Seed modules at 150 mA each from 5 V
- Total 5 V current: 0.45 A
- 5 V output power: 2.25 W
- Estimated 9 V input current at 85% buck efficiency: 0.294 A
Protection sizing:
- 500 mA PTC is above estimated 0.294 A input current and matches the original requirement.
- AP63205 2 A output rating gives large margin over the 0.45 A estimated load.
Validation Status
Electrical rule check returned no ERROR or WARNING results after schematic wiring.
Current design-rule issues are layout-only: airwires and overlapping copper appear because components are not yet placed or routed. These are expected before PCB layout and are not schematic wiring failures.
Important Layout Notes for Next Phase
- Place U1, L1, C1, C2, C3, and C4 tightly together per buck-converter best practice.
- Keep the SW node compact and away from audio/USB traces.
- Route 5 V power traces at least 0.8 mm as specified, or wider if practical.
- USB D+/D- should be routed as short, paired traces. A 2-layer board can work for short internal USB pigtails, but controlled impedance is limited.
- Keep audio chain traces away from the buck SW node and inductor.
- Connect USB connector shield/mount pins to CHASSIS, with CHASSIS coupled to PCB GND through R1/C6.
Next Step
Proceed to PCB layout setup for the power/interconnect board: 90 mm x 40 mm, Standard 2 Layer, then placement. Placement should group power components tightly and keep audio/USB connectors at the board edges.
Implemented Schematic Scope
Buck Regulator Selection
Power Budget
Validation Status
Important Layout Notes for Next Phase
Next Step
