Tx and Rx max. pulse duration for ZigBee Protocol

[Rahul]

Dear Nordic Team, 

We are using nRF52840 based module and using its ZigBee Radio. For one certification purpose, we need to know the max. pulse time (duration) for Tx and Rx single pulse. Consider max. the payload for Zigbee and max. RF power - 8dBm of IC. 

We also want the max. current drawn for 3.3V at max. Tx power without PA.  

For Bluetooth, we can figure it out from your online power profiler kit, but for ZigBee, it's not available.  

Regards, 

Rahul Shah 

IIoT Consultant | [email protected] 

[ketiljo]

Maximum TX duty cycle for the TX is ~60%. But you will make is easier by stating 100% to avoid any duty cycle restrictions.  

You can find the TX current draw numbers in the PS:  https://infocenter.nordicsemi.com/topic/ps_nrf52840/radio.html#unique_737946918

[Rahul]

ketiljo said:

Maximum TX duty cycle for the TX is ~60%. But you will make is easier by stating 100% to avoid any duty cycle restrictions. 

Is there any reference document where this is mentioned? We need to provide evidence from the manufacturer to our certification agency. 

Also, is this ~60% duty cycle configurable? If yes, how?  

[Rahul]

Just FYI, we have to get the device certified for IEC Ex/ATEX Ex ia (Zone 0 Hazardous location) and as per IEC60079-0, the max. RF pulse duration (in air) should be less than 20uS and power should not exceed 2W. 

For power, we are well within the limits but for the period it is a concern. Probably due to this reason, we may not consider 100% duty cycle. 

[ketiljo]

Less than 20 µs will be hard and virtually impossible. There is usually a relationship between output power and pulse time, so then the output power is low, the pulse time can be longer. 

A standard 802.15.4 Zigbee packet is 127 bytes at 250 kbps. This takes ~4 ms to transmit.