ESP32-S3 PLC Architecture Discussion
Worked for 15 mins 44 sec
Completed the final schematic-gate pass and updated Schematic Review Before Layout. D29 is verified, L2 is now a confirmed shielded Sumida inductor, and U8/U9 FAULT is routed to ESP32 GPIO15 with a 10kΩ pull-up; ERC remains clean.
Open items:
- Layout is still not approved: HR911105A symbol-footprint mapping remains Must Fix because the Flux symbol/footprint readout is ambiguous versus the datasheet.
Suggested next steps:
- Replace HR911105A with a clearly numbered MagJack part/footprint, or manually verify its symbol-footprint mapping.
- After that, update the approval table to “Pass” and proceed to PCB placement.
HOW TO DOWNLOAD SCHEMATIC AS PDF OR AS A ALTIUM PROJECT?
Thought for 8 sec
In Flux, use the Export options from the project UI:
- Open your project.
- Click Export / download from the top toolbar or project menu.
- Choose:
- PDF for schematic/documentation output.
- Altium if available in your export list; otherwise export standard manufacturing/interchange formats such as Gerber, ODB++, IPC-2581, BOM, and Pick-and-Place.
If you don’t see an Altium export option, Flux may not support direct Altium project export for this project. For help from Flux support, use: https://docs.flux.ai/Introduction/getting-support.
Export and verify files
Export schematic PDF
Export BOM files
Generate manufacturing files
Create export checklist
Thought for 3 sec
Refine this doc
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ESP32-S3 Industrial PLC Controller — Cost-Optimized IC Selection
Locked schematic-capture decision
Use the revised isolated RS485 power architecture:
+24V_PROT → 24V-to-5V buck → +5V → 5V-to-5V isolated DC-DC → ISO_5V / ISO_GNDThe final pre-schematic power budget showed the original 1 A LMR51610 does not meet the required 30% buck-current margin. The 24 V-to-5 V buck is now locked to the higher-current TI LMR51625 family for schematic capture.
Locked preferred schematic-capture list
Table
| Block | Locked preferred part | Qty | Decision |
|---|---|---|---|
| MCU | ESP32-S3-WROOM-1-N16R8 | 1 | Required MCU module. |
| Ethernet | W5500 SPI Ethernet controller | 1 | Required W5500-only Ethernet architecture. |
| 24 V to +5 V buck | TI LMR51625 | 1 | Replaces LMR51610 after power-budget margin check. Use 60 V / 2.5 A class buck pending exact suffix/library availability. |
| 5 V to +3V3 logic regulator | Switching 3.3 V regulator preferred | 1 | Avoid high LDO dissipation at peak 3.3 V load. Exact part to select during power block capture. |
| Isolated RS485 transceiver | TI ISO1410BDWR / ISO1410DWR | 1 | Keep isolated RS485. No non-isolated substitution. |
| ISO_5V isolated supply | Mornsun B0505S-1WR3 | 1 | 5 V-to-isolated-5 V module powered from +5 V. Output is ISO_5V / ISO_GND. |
| Digital inputs | 8× PC817 optocoupler-based 24 V PNP/sourcing DI channels | 8 | Keep 8 channels. Use PC817 family with proper resistor/filter/protection. |
| Digital outputs | 2× TI TPS4H160BQPWPRQ1 | 2 | 8 protected high-side 24 V outputs, ≥0.5 A/channel. |
Reliability constraints retained
- RS485 remains galvanically isolated using ISO1410 plus isolated
ISO_5Vsupply. ISO_GNDmust not be tied to normalGND.- 8 DI channels and 8 DO channels are unchanged.
- W5500 SPI Ethernet is unchanged.
- Buck regulator still needs industrial input protection: fuse/PTC, reverse protection, TVS/clamp, input filtering, and layout appropriate for switch-mode supplies.
- 5V-to-5V isolated modules are unregulated/noisy compared with larger converters; add ISO-side decoupling, consider ferrite/LC filtering, and keep the module/ISO1410 isolation barrier layout clean.
Power-budget result driving the LMR51625 decision
Calculated conservative
+5V peak load before schematic capture is about 829 mA. A 1 A LMR51610 provides only about 21% margin, below the requested 30% minimum. A 2.5 A LMR51625-class buck gives ample current margin while retaining industrial input voltage capability.Schematic capture order
- 24 V input protection and
+5V/+3V3/ISO_5Vpower tree. - ESP32-S3-WROOM-1-N16R8 core.
- USB-C programming/debug.
- W5500 SPI Ethernet.
- ISO1410 isolated RS485.
- 8 PC817-based digital inputs.
- 8 TPS4H160-based high-side outputs.
- Connectors, LEDs, test points, and final review.
Locked schematic-capture decision
Locked preferred schematic-capture list
Reliability constraints retained
Power-budget result driving the LMR51625 decision
Schematic capture order
