PCB Design for Fog Generator
Worked
Stopped by execution credits before I could finish the full schematic update or run ERC.
Completed so far:
- Removed obsolete 14 V parallel ideal-diode mux parts: U10/U11, Q10/Q11, C1/C2, R1–R4.
- Removed old TPS563200 17 V buck section: U3, L1, C5–C9, R5–R7.
- Removed old pump MOSFET driver and 2-pin pump connector: Q2, R16, R17, D2, J4.
- Renamed global power nets:
+14V_BUS→+28V_BUS+14V_MUX→+28V_OR_PRE_FUSEVBAT_A_IN→VBAT_SERIES_INPUMP_PWM→STEPPER_STEP
- Added main new 28 V architecture parts:
- U_BB LM5175PWPT buck-boost controller
- U3 TPS54561DPRT wide-VIN 3.3 V buck regulator
- J12 logical 6-pin LEMO input connector
- J4 5-pin JST-XH stepper pump connector
- U_DIODE_1/U_DIODE_2 LM74700-Q1 ideal-diode OR controllers
- Q_DIODE_1/Q_DIODE_2/Q_BB1–Q_BB4 using TSM170N06CP_ROG 60 V / 38 A MOSFETs as library substitutes because FDP18N40 was not found
- L_BB 47 µH / 15 A generic inductor placeholder
- Added and partially wired:
- LEMO input filter caps
- LM5175 bootstrap, soft-start, compensation, RT, UVLO, and feedback passives
- LM74700 1 µF VCAP bypass caps and gate networks
- TPS54561 input/output caps, bootstrap cap, feedback divider, EN/UVLO, SS, RT, and compensation placeholders
- Stepper connector pins for
+28V_BUS,GND,STEPPER_STEP,STEPPER_DIR,STEPPER_ENABLE
- Updated existing metadata:
- C3 to 4700 µF / 50 V bulk
- C4 to 50 V HF bypass
- F1 marked 25 A / 50 V minimum requirement
- J3 heater label/role updated for 28 V 200 W
- Q1 metadata updated to the 60 V MOSFET substitute
Important unresolved items:
- ERC has not been run after these edits.
- LM5175 datasheet correction: LM5175 VIN max is 42 V, not 60 V. It may still work for a 28 V system, but it is not a 60 V input controller.
- The exact LEMO EGG.1B.306 library footprint was not found; J12 is currently a logical 6-pin connector placeholder.
- The LM5175 current-sense implementation is only placeholder-wired; the proper high-power current-sense resistor/network still needs detailed design.
- INA226 monitor wiring is not fully resolved after the architecture change; U6B/R21 are still in an intermediate/orphaned state and need reconnection to the intended +28 V measurement point.
- PCB layout is now invalid for this revised architecture and will need a fresh placement/routing pass after the schematic is cleaned.
Clean unresolved issues
Run ERC/DRC
Find 60V controller
Find LEMO footprint
Design current sense
Refine this doc
Ask about this doc
BOM Sourcing Audit — Phantom Fogger Control Unit V1
Date: 2026-05-26
Summary
I walked the BOM for sourcing, lifecycle, and manufacturability risk. The manufacturing MPN review now reports no open errors/warnings, and the parts-availability review reports no open errors/warnings.
Changes Made
-
Replaced the out-of-stock amber fault LED:
- Removed: PARALIGHT LC191JFCT-UEI, LCSC C729291, no LCSC stock.
- Added: Broadcom HSMA-C190, amber 0603 LED.
- Reason: HSMA-C190 has strong stock at Digi-Key, Mouser, TME, and some LCSC/HQonline availability.
- Connectivity restored: D4 anode to FAULT_LED_A, cathode to GND.
-
Assigned exact sourced MPNs to generic passives:
- 0603 resistors: Yageo RC0603FR series by value.
- 0.1 uF MLCCs: Samsung CL10B104KB8NNNC.
- 10 nF MLCCs: Samsung CL10B103KB8NNNC.
- 1 uF / 35 V MLCCs: Samsung CL31B105KBHNNNE.
- 10 uF input MLCC: Samsung CL31B106KBHNNNE.
- 22 uF output MLCC: Samsung CL21A226KAYNNNE.
- 10 uF local low-voltage MLCCs: Samsung CL21A106KOQNNNE.
- 4700 uF / 35 V bulk capacitor: Panasonic EEU-FR1V472.
- 5 mΩ 2512 shunts: Bourns CSS2H-2512R-L500F.
- Buck inductor: Coilcraft XAL7030-103MEC, 10 uH shielded, 5.3 A rating.
-
Corrected the large bulk capacitor package:
- C3 was previously a generic capacitor with an impossible 0603 package for 4700 uF / 35 V.
- Updated to a radial electrolytic footprint class: CP_Radial_D18.0mm_P7.50mm.
Sourcing Notes by Functional Part
Table
| Part / group | Status | Notes |
|---|---|---|
| ESP32-S3-WROOM-1-N16 | OK | Active and stocked at Digi-Key, Mouser, LCSC, HQonline, TME. |
| LM74700QDBVTQ1 | OK | Active and stocked at Digi-Key/Mouser; limited but present LCSC/HQonline. |
| FDP8030L MOSFETs | Acceptable with note | Digi-Key stock exists, but Mouser/Verical showed obsolete flags. No better TO-220/D2PAK Flux-library replacement was found that met =30 A. Keep for v1, but monitor before production buy. |
| TPS563200DDCR | OK | Active and stocked at Digi-Key, Mouser, Verical, TME; LCSC currently zero. |
| XAL7030-103MEC inductor | OK | Stocked at Mouser, Digi-Key, and LCSC; good current margin for the 3 A buck. |
| MAX31855KASA+ | Acceptable with note | Active; Digi-Key stock good, Mouser low stock. High cost; acceptable for prototype/v1. |
| MAX3485ESA+ | OK | Stocked at Digi-Key, Mouser, LCSC, Verical. |
| INA226AIDGSR | OK | Stocked broadly including LCSC, Digi-Key, Mouser. |
| USB4105-GF-A USB-C | OK | Strong Digi-Key/Mouser/Verical stock. |
| B2B-XH-AM(LF)(SN) | OK | Broadly stocked. |
| XY301V-A-5.0-2P terminals | OK | LCSC stock. |
| Würth 691137710005 DMX connector placeholder | OK for PCB placeholder | Stocked at Digi-Key/Mouser. Note: this is a screw-terminal representation of off-board/panel XLR wiring, not the Neutrik panel connector itself. |
| Littelfuse 178.6764.0001 fuse holder | OK with electrical note | Stocked broadly. Holder rating is up to 30 A max / about 22 A continuous, so it is acceptable for 14 A heater current but should be checked if a true continuous 25 A load is expected. |
| 1N4007G flyback diode | OK | Broad stock; adequate for small pump flyback, though a Schottky can reduce recovery noise if needed. |
| UI tact switches | OK | Very strong LCSC stock. |
| LEDs | OK | Green and red LEDs stocked; amber fault LED substituted to Broadcom HSMA-C190. |
Remaining Recommendations
- Before layout release, confirm whether the design should use Neutrik panel-mount XLR connectors directly on the PCB or keep the current PCB terminal/harness representation for off-board XLRs.
- For production, re-check FDP8030L lifecycle. If the obsolescence flags become a procurement issue, request or create a modern TO-220/D2PAK MOSFET part in Flux and replace all three high-current MOSFETs.
- During layout, update footprints/placement for C3 bulk electrolytic and any large passives whose package changed during sourcing cleanup.
Validation
- Manufacturer Part Number review: no open errors/warnings after cleanup.
- Parts availability review: no open errors/warnings after D4 substitution and passive MPN assignment.
Summary
Changes Made
Sourcing Notes by Functional Part
Remaining Recommendations
Validation
