Configuration nRF52820 - RADIO: External PAs, FEMs, and LNAs need additional Radio configuration

This configuration applies to Revision 3, build codes QDAA-Dx0, CFAA-Dx0.

Symptoms

When transmitting in IEEE802.15.4 mode with an external RF Front End Module (FEM) or Power Amplifier (PA), the power emitted in adjacent RF channels might violate the requirements in section TP/154/PHY24/TRANSMIT-05 of the ZigBee IEEE 802.15.4 Test Specification. When receiving in any radio mode with an external high-gain FEM or Low Noise Amplifier (LNA), the amplified signal might negatively impact the blocking performance of the combination of the nRF52 device and the FEM or LNA.

Conditions

Operating with an external RF frontend. Devices with date code 2150 or later.

Workaround

Apply the following code before enabling the RADIO in any radio mode:


 if (*(volatile uint32_t *) 0x10000330ul != 0xFFFFFFFFul) {
     *(volatile uint32_t *) 0x4000174Cul = *(volatile uint32_t *) 0x10000330ul;
 }

Apply the following code before enabling the RADIO in 802.15.4 mode:


 if (*(volatile uint32_t *) 0x10000334ul != 0xFFFFFFFFul) {
     *(volatile uint32_t *) 0x40001584ul = *(volatile uint32_t *) 0x10000334ul;
 }
 if (*(volatile uint32_t *) 0x10000338ul != 0xFFFFFFFFul) {
     *(volatile uint32_t *) 0x40001588ul = *(volatile uint32_t *) 0x10000338ul;
 }

If entering another RADIO mode after mode 802.15.4, apply the following code before enabling the RADIO:


 if (*(volatile uint32_t *) 0x10000334ul != 0xFFFFFFFFul) {
     *(volatile uint32_t *) 0x40001584ul = ((*(volatile uint32_t *) 0x40001584ul) & 0xBFFFFFFul) | 0x00010000ul;
 }
 if (*(volatile uint32_t *) 0x10000338ul != 0xFFFFFFFFul) {
     *(volatile uint32_t *) 0x40001588ul = ((*(volatile uint32_t *) 0x40001588ul) & 0xBFFFFFFul);
 }

This workaround is included in nRF Connect SDK 1.7 and later.

[256] RADIO: External PAs, FEMs, and LNAs need additional Radio configuration

Symptoms

Conditions

Workaround