USB-C Temperature and Humidity Sensor Design


Screenshot 2026-04-08 150224.png

That screenshot looks like a compact 4-layer automotive dongle-style PCB reference, and the main takeaway for your current project is its placement strategy, not its exact circuitry. Per the attachment-analysis workflow, the right way to use an uploaded image like this is to extract the visible architecture and relate it to your open design context rather than treat it in isolation
For your USB-C environmental sensor node, the useful ideas to borrow are:
  • Put the input connector and protection stage together near the board edge
  • Keep the MCU/module in a clean area with short power decoupling paths
  • Reserve a clear antenna keep-out at the board edge if you use a radio module
  • Keep the sensor away from local heat sources like the regulator and protection IC
  • Use the 4-layer structure as:
    • L1: signals/components
    • L2: solid GND
    • L3: 5 V / 3.3 V distribution
    • L4: secondary signals + local GND pour
What does not carry over well from that reference:
  • Automotive connector placement and 12 V protection assumptions
  • High-current/vehicle-interface routing priorities
  • OBD-style mechanical outline
So: yes, it is a good layout reference for floorplanning, especially connector-edge placement, RF keep-out discipline, and power-entry clustering. But for your project, I’d adapt it into a USB-C on one edge, protection + regulator immediately behind it, MCU near antenna edge, sensor thermally isolated layout.
If you want, I can next:
  • set your board to a 4-layer layout,
  • size it for a small consumer sensor node,
  • and define the placement/rule strategy for the current project.
Set 4-layer stackup
Suggest board size
Place key blocks

U1
U3
Not Recommended for New Designs
C2
Capacitance
100nF
U2
J1
U4
C1
Capacitance
10uF
C4
Capacitance
10uF
C3
Capacitance
1uF
U1 LX3 - U2 VIN
J1 SHELL_GND - R1 P2
J1 SHELL_GND - R1 P2
U3 EN - R5 P2
J1 VBUS_A - J1 VBUS_B
U3 GND - U4 VSS
U2 VOUT - U3 3V3
J1 VBUS_A - J1 VBUS_B
J1 SHELL_GND - R1 P2
U4 SCL - U3 IO5
U4 SDA - U3 IO4
U3 GND - U4 VSS
U2 VOUT - U3 3V3
J1 VBUS_A - J1 VBUS_B
J1 CC2 - R2 P1
R1
Resistance
5.1kΩ
U1 PAD - U2 GND
J1 CC1 - R1 P1
U1 LX3 - U2 VIN
R2
Resistance
5.1kΩ
GND
J1 VBUS_A - J1 VBUS_B
U2 EN - U1 VCC
U1 PAD - U2 GND
J1 CC2 - R2 P1
GND
U2 EN - U1 VCC
J1 SHELL_GND - R1 P2
J1 SHELL_GND - R1 P2
J1 CC1 - R1 P1
U4 SCL - U3 IO5
U2 EN - U1 VCC
U3 GND - U4 VSS
J1 SHELL_GND - R1 P2
U4 SDA - U3 IO4
U2 VOUT - U3 3V3
J1 VBUS_A - J1 VBUS_B

USB-C Environmental Sensor Node

USB-C Environmental Sensor Node thumbnail