51822 power consumption issue with PA added

Question

Hi Everyone, 
 RFX2411N is used to extend signal coverage of NRF51822. Here are the configuration below: 
 
 Use radio notification to generate an interrupt 
 Use this interrupt and a GPIO pin to control RXEN. 
 Connect VDD_PA to TXEN and let this control the switching between PA and LNA mode. 
 
 And the problem is: 
 sometimes radio signal interrupt is missed which causes incorrect GPIO configuration. Thus power consumption is pretty high. 
 We have quite a few products in field with customer complain about the power consumption issue.

AmbystomaLabs · Accepted Answer

Here is some code for you to work with. It will completely replace your other logic. I recommend you keep the notification distance to a minimum since this will reduce your battery consumption. Here is the table for NRF_RADIO->STATE from the reference manual: I am making the assumption that the radio knows which state it will be in when you get the notification. You could hedge your bet on this by turning on the LNA for either RxRu, RxIdle, in addition to Rx. Here is the code: #include "ble_radio_notification.h" #define RADIO_NOTIFICATION_IRQ_PRIORITY 2 #define RADIO_NOTIFICATION_DISTANCE NRF_RADIO_NOTIFICATION_DISTANCE_800US void radio_notification_evt_handler(bool radio_evt) { if (radio_evt && (NRF_RADIO->STATE==0x3)) { NRF_GPIO->OUTSET = (1UL<<22); } else { NRF_GPIO->OUTCLR = (1UL<<22); } } //Include this in main AFTER you have started the SD but BEFORE you start advertising. err_code=ble_radio_notification_init(RADIO_NOTIFICATION_IRQ_PRIORITY,RADIO_NOTIFICATION_DISTANCE,radio_notification_evt_handler); APP_ERROR_CHECK(err_code); You will notice I just clear the RX pin without logic. It doesn't really matter if we clear it after a Tx event and it is safer to just make sure it is cleared whenever it shouldn't be on.

AmbystomaLabs · Answer

If you ever do a rev of this board you should terminate ANTA into 50 ohms since you are not using it. 
 RF switches can fry easily with open circuits due to the high voltages that can be present. Better to be safe and just terminate unused RF ports.

51822 power consumption issue with PA added

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