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
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ESP32-S3 Industrial PLC Controller — Candidate IC Selection
Scope
Candidate IC/component selections for the detailed schematic phase. These are recommended starting points and must still be verified against the latest datasheets, thermal calculations, package/footprint availability, and sourcing before layout release.
Selected candidate table
Table
| Block | Selected part | Manufacturer | Rating / key specs | Reason for selection | Alternative part | Risks / availability concerns |
|---|---|---|---|---|---|---|
| MCU | ESP32-S3-WROOM-1-N16R8 | Espressif Systems | 3.0–3.6 V module, Wi-Fi/BLE, 16 MB flash, 8 MB PSRAM, native USB/JTAG capability | Mandatory project requirement; integrates RF and memory; suitable for Modbus TCP/RTU gateway/control firmware | None for this design; user explicitly requires this module | Operating temperature/version and exact antenna keepout must be verified from chosen module datasheet and footprint. |
| Ethernet | W5500 | WIZnet | SPI 10/100 Ethernet controller, LQFP-48 class device | Mandatory W5500-only architecture; avoids ESP32 native Ethernet MAC/RMII PHY requirement; good Modbus TCP fit | None unless user changes Ethernet requirement | Needs crystal/clock, magnetics/MagJack, proper Ethernet ESD, and SPI bandwidth/GPIO allocation review. |
| 24 V to 5 V buck | TPS54360DDA | Texas Instruments | 4.5–60 V input, 3.5 A step-down buck, -40 to 125 °C class, PowerPAD/SO-PowerPAD package | Meets 18–36 V input with 60 V margin; enough current for logic and downstream rails; common industrial buck family | LM5013DDAR, 6–100 V input buck; TPS54531DDA if VIN/surge margins check out | Must calculate actual load and thermal dissipation. 60 V VIN does not replace input surge clamping; TVS/clamp must keep switch node/input within ratings. |
| 5 V to 3.3 V logic regulator | AMS1117-3.3RG initially acceptable for prototype; prefer a lower-Iq/thermal-checked LDO or small buck if load is high | Advanced Monolithic Systems / compatible vendors | Fixed 3.3 V, up to 1 A, SOT-223 class | Simple and widely available for prototype; can power ESP32-S3, W5500, and logic if thermal budget permits | LTC3406B buck for better efficiency; TI TLV76733 / AP7365 / similar modern LDO if available in library | AMS1117 dissipates (5 V - 3.3 V) × Iload; may run hot with ESP32 + W5500 peaks. Final selection should follow measured/calculated current budget. |
| Isolated RS485 transceiver | ISO1410BDWR or ISO1410DW | Texas Instruments | Galvanically isolated RS485/RS422 transceiver, SOIC-16 wide package, external isolated field supply required | Best architectural fit because the project already requires separate ISO_5V / ISO_GND; supports true isolated RS485 without tying grounds | ISO1430BDW/ISO1430DWR, ADM2483BRWZ, ADM2587EBRWZ, MAXM22511GLH+ | Flux library has ISO1410 variants but some entries lack attached datasheets; verify exact suffix, isolation rating, bus voltage, failsafe, and 3.3 V logic compatibility. ADM2587E includes isoPower and may be redundant with separate ISO_5V. |
| Isolated 24 V to ISO_5V DC-DC | RS6-2405S | RECOM Power | 18–36 V input, isolated 5 V output, 1.2 A / ~6 W class | Found in library and electrically matches 24 V industrial input to ISO_5V; ample current for isolated RS485 field side | Lower-power 1–2 W 24 V-to-5 V isolated modules from Murata/RECOM/Traco if available and footprint acceptable | Overpowered for RS485 only; size/cost/no-load behavior may be unnecessary. Search did not find a smaller exact 1–2 W library match. |
| Digital input optocouplers | PC817X1CSP9F, quantity 8 | Sharp / Socle PC817 family | Single-channel phototransistor optocoupler, ~5000 Vrms isolation class; PC817 family CTR commonly binned around 50–600% depending suffix | Common, low-cost, available SMD optocoupler; works for 24 V PNP DI with external reverse protection, current limit, RC filter, LED, and 3.3 V pull-up | PC817X3NIP2B, PC817XNNIP0F, LTV-817, TLP290, ACPL/KCA family optos | CTR bin and temperature aging affect resistor/pull-up sizing. For IEC 61131-2 compliance or high channel density, a digital-input receiver IC/opto array may be better. |
| Digital output high-side drivers | ITS724G, quantity 2 | Infineon | Quad smart high-side switch, 5.5–40 V operating supply, 4 × 90 mΩ, industrial PROFET family; integrated protection/diagnostics | Directly matches two quad-channel smart high-side driver preference; supports 8 sourcing outputs at ≥0.5 A/channel with margin | Infineon PROFET+2 4-channel family such as BTS700x/BTT6xxx variants if library/availability allows; ST VNI8200XP-class 8-channel industrial driver if diagnostics/protocol fit | Check lifecycle/package availability, per-channel thermal dissipation at simultaneous load, diagnostic interface details, clamp energy for inductive loads, and logic-level input compatibility. |
| USB-C protection/power path | TBD during USB block schematic | Multiple | USB 2.0 device, CC Rd resistors, D+/D- ESD, VBUS detect, ideal-diode / load-switch path for logic-only power | Needs to be selected with ESP32-S3 native USB vs USB-UART decision and power tree details | TPD2EUSB30/TUSB ESD class, AP2331/TPS load switch, ideal-diode ORing devices | Do not let USB back-feed +24V_PROT, isolated supply, field I/O, or high-side outputs. |
Recommended selections for next schematic pass
- Use TPS54360DDA for the 24 V-to-5 V buck regulator.
- Use ISO1410BDWR / ISO1410DW as the primary isolated RS485 transceiver candidate, powered field-side from
ISO_5V/ISO_GND. - Use RS6-2405S only as the initial library-available isolated DC-DC candidate; continue searching for a smaller 1–2 W 24 V-to-5 V isolated module before final BOM lock.
- Use 8× PC817X1CSP9F as prototype DI optocouplers unless IEC 61131-2 input-class compliance forces a more specific industrial input solution.
- Use 2× ITS724G as the initial 8-channel high-side output solution.
- Treat AMS1117-3.3RG as a prototype placeholder only until the +3.3 V current and thermal budget is calculated; a more efficient 3.3 V regulator may be required.
Notes for detailed schematic capture
- The W5500 and ESP32-S3 choices are fixed by requirement.
- The isolated RS485 choice should not use native Ethernet PHYs or affect W5500 architecture.
ISO_GNDmust remain isolated from normalGND; no direct short.- USB debug power must be logic-only and isolated from 24 V and field domains.
- High-side output LED indication should be designed so it reflects output/channel status without compromising driver diagnostics or leakage limits.
- DI input resistor power ratings must be checked for 36 V continuous and surge/EFT stress; 0805/1206 resistors may be needed.
Scope
Selected candidate table
Recommended selections for next schematic pass
Notes for detailed schematic capture
