1. Project Overview
We are developing a Gateway for our Cattle Monitoring project using Nordic Semiconductor's nRF54LM20A SoC and nRF21540 RF front-end module (FEM).
We would like the Nordic Semiconductor team to review our schematic and PCB layout to identify any potential hardware design issues and verify compliance with the recommended design guidelines before proceeding with PCB fabrication and production.
2. Hardware Details
-
Project: Cattle Monitoring Gateway
-
Main SoC: nRF54LM20A-PAAA-R
-
RF Front-End: nRF21540-QDAA-R
-
Operating Frequency: 2.4 GHz ISM band
-
PCB Stack-up: 4-layer PCB
-
RF Interface: 50 Ω impedance-controlled RF transmission lines
-
External DC Input: 5 V to 10 V
-
Battery: 1S2P Li-ion battery pack
-
Cellular Module: Quectel EC800M
3. Scope of Validation Requested
We request Nordic's review and feedback on the following areas:
A. Schematic Review
-
Verify the nRF54LM20A power supply, decoupling capacitors, reset and boot-related circuitry, and SWD programming/debug interface.
-
Review the nRF21540 power supply, control signals, and interface connections to the SoC.
-
Verify the recommended connections for FEM control signals, including MODE, ANT_SEL, and PDN, as applicable to our configuration.
-
Review the external crystal/clock circuitry, RF connections, and other mandatory components against the datasheet and reference design.
-
Identify any missing components or recommended circuit modifications.
B. RF Design and Matching Network
-
Review the RF interface between the nRF54LM20A and nRF21540.
-
Validate the RF matching network and recommended component placement.
-
Review the 50 Ω impedance-controlled RF transmission lines and PCB routing.
-
Verify the RF port configuration, antenna selection, and relevant FEM operating modes.
-
Provide recommendations for minimizing RF losses and improving wireless performance.
C. PCB Layout Review
-
Review the 4-layer PCB stack-up and grounding strategy.
-
Verify the placement of decoupling capacitors and RF components.
-
Review the RF ground reference, ground vias, return paths, and antenna feed routing.
-
Check component placement and routing around the SoC, FEM, and RF matching network.
-
Identify any layout changes required before fabrication.
D. Design Recommendations
-
Please highlight any deviations from Nordic's recommended reference designs or hardware design guidelines.
-
Kindly provide specific schematic or PCB layout corrections wherever necessary.
-
Please confirm whether the design is suitable to proceed to the next stage after addressing the review comments.
4. Files Attached for Review
We will attach the following design files to this ticket:
-
Gateway schematic PDF.
-
Gerber fabrication files.
- Gateway_V3_Final_Files.zip
5. Expected Outcome
Our objective is to complete the hardware design review before proceeding with PCB fabrication and prototype assembly.
We request Nordic's feedback on the schematic, RF design, component selection, and PCB layout, including any mandatory changes or recommendations required to improve design reliability and RF performance.