USB-C Sensor Node
Worked for 1 min 8 sec
Thought for 47 sec — Searching for eFuse solutions
Found 4 results for TPS25942.
Found 3 results for TPS25944.
Found 3 results for Find eFuse with true reverse current blocking back-to-back FET for 5 V USB-C input, includes OVP UVLO OCP adjustable current limit around 1 A, available in Flux library, active SMD part. Candidate TI TPS25942 TPS25944 or similar..
Thought for 43 sec
Thought for 18 sec — Planning component replacement
Read TPS25940LRVCR tps25940.pdf.
Thought for 1 min 36 sec
Thought for a moment
Calculating resistor values
I need to replace some components in my circuit, specifically requiring RILIM for 1A with an equation that seems a bit off. For R = 88.7k, this gives 0.99A, so R3 must change from 909Ω to 88.7k. I also want to set up an OVP/UVLO divider using resistors R1, R2, R3 and see if I can repurpose the existing R5, R6, and R4. I need to calculate the appropriate values based on thresholds for VUV and VOV while ensuring everything fits correctly in the designed circuit.
Considering IMON resistor
I'm thinking about whether I need to add an IMON resistor to my circuit. If it's going to be unused, I might just leave it out altogether. It's important that I carefully evaluate its purpose, so I don't add unnecessary components. I want to keep the design clean and functional, so if the IMON resistor isn't needed, I should definitely skip it to simplify things. Let’s carefully decide based on the overall circuit requirements
i not view sample
Thought for 3 sec
The project schematic exists with the USB‑C connector, protected 5 V input, 3.3 V regulator, SiWG917 Wi‑Fi/BLE module, and SHT41 temperature/humidity sensor.
I can’t generate or display the sample right now because no ACUs are available. Remaining work: verify wiring/ERC, fix any schematic issues, organize the schematic visually, and complete PCB placement/routing.
Technical Construction File — USB-C WiFi BLE TH Sensor
Status
Draft — schematic-stage regulatory file.
Applicable Regulations
- FCC Part 15 intentional radiator / unintentional radiator
- CE RED for EU radio equipment
- ISED Canada if sold in Canada
- UKCA if sold in the UK
- RoHS/REACH for consumer production
Product Description
USB-C powered indoor consumer temperature/humidity sensor node using a Silicon Labs SiWG917 Wi-Fi/BLE module and Sensirion SHT41 digital T/RH sensor.
Wireless Technology Summary
Table
| Module | MPN | Technology | Frequency Band | Antenna | Notes |
|---|---|---|---|---|---|
| U1 | SIWG917Y111MGABAR | Wi-Fi 2.4 GHz 802.11 b/g/n/ax + BLE 5.4 | 2.4 GHz ISM | Integrated antenna variant | Must follow Silicon Labs integration/keepout guidance |
Required Documentation Checklist
- Product block diagram — included in Project Specification
- Draft BOM from schematic — available in Flux BOM
- RF integration notes — included below
- Draft Declaration of Conformity — created in this file
- User manual outline — included below
- Final schematic PDF export
- Final PCB layout/Gerbers after layout
- Module certification grants and integration manual from Silicon Labs
- EMC/RF test reports from accredited lab
- Final product labels with FCC/CE/UKCA marking
RF Design Notes
- U1 must be placed at a PCB edge with the integrated antenna facing outward.
- Keep the antenna clearance void of copper, traces, vias, components, and metal on all layers.
- Keep U3/L1 buck regulator switch node and inductor away from U1 antenna region.
- Maintain solid ground under the module body where allowed by the module datasheet.
- Do not change the module antenna or add metal/plastic in direct contact with the antenna without RF validation.
Draft Declaration of Conformity
We, [Company Name], declare that the product USB-C WiFi BLE TH Sensor is designed to conform to applicable FCC Part 15, CE RED, RoHS, and EMC requirements when manufactured and integrated according to the final approved schematic, PCB layout, BOM, RF module integration guide, and user manual.
Authorized signatory: ____________________
Date: ____________________
User Manual Outline
- Product overview and intended indoor consumer use.
- USB-C 5 V power-only input requirements.
- Wireless setup/provisioning instructions.
- Temperature/humidity measurement limitations; avoid direct sunlight, condensation, and heat sources.
- Regulatory notices: FCC Part 15 statements, CE/UKCA marking, RF exposure statement, no user-serviceable RF modifications.
- Disposal and RoHS/WEEE notes.
Open Items
- Confirm exact SiWG917 certification IDs and approved integration conditions.
- Add final PCB layout screenshots/exports after layout.
- Run EMC pre-scan with USB cable attached and Wi-Fi/BLE active.
Status
Applicable Regulations
Product Description
Wireless Technology Summary
Required Documentation Checklist
RF Design Notes
Draft Declaration of Conformity
User Manual Outline
Open Items