RF-PHY TX Pre-Compliance Health Check: Nordic nRF52832

This project involved a deep-dive RF performance audit of a Nordic Semiconductor PCA10040 (nRF52832) development board to ensure adherence to Bluetooth Core Spec v5.x. Using the Optima BLE Tester, we validated key transmitter metrics including output power, frequency drift, and modulation accuracy. The result was as “PASS”. Optima Test Labs confirmed the great performance of the Nrf52832 and confirmed why it is has been one of the most reliable BLE solutions in the market.

Nordic nRF52832 SoC

The Challenge & Setup

  • Objective: Validate transmitter health under DTM (Direct Test Mode).

  • Interface: Conducted testing via u.FL to SMA pigtail for maximum signal integrity.

  • Stack: Nordic nRF52832 SoC running DTM over HCI (19200 baud).

Performance Metrics & Results

  • Output Power: Expected 0dBm. Consistent at +0.02 dBm across all channels (0, 19, 39).

  • Frequency Offset: Measured at 17.269 kHz (well within the ±150 kHz limit).

  • Modulation Index: Achieved 0.96, exceeding the >0.8 requirement.

Nordic nRF52832 SoC

Diagnostic Analysis

When using NRF52832 in your design, Optima Test labs recommends to take a look into the following Hardware considerations

  • Frequency Analysis: Using the PCA10040 as a “reference”, confirmed the crystals used in the custom board have equal of better specifications. In mass production it is recommended to inspect crystal lots used on each build.

  • Hardware Refinement: Suggested moving the DC-DC power inductor further from RF traces to reduce potential interference.

  • Antenna Tuning: Recommended re-tuning the Pi-network due to custom enclosure resonance shifts.