Interfacing PA with nRF51822

RE: Interfacing PA with nRF51822

Sreekanth — Thu, 19 Nov 2015 07:17:38 GMT

Hi,

Can CC2592 PA from TI can be used with nRF51822?

RE: Interfacing PA with nRF51822

Sreekanth — Tue, 17 Nov 2015 14:28:04 GMT

Hi, Does nRF51822 QFN package has internal Balun?

Thanks, Sreekanth

RE: Interfacing PA with nRF51822

Sreekanth — Tue, 17 Nov 2015 09:49:15 GMT

Hi Hakon,

Thanks for the answer.

After posting my question in the Nordic forum, I again went through the datasheet of both the PA and I planned to use nRF51822 with integrated balun and SE2431L.

As far as the bluetooth core spec, in certain condition only we need to increase the power of the bluetooth as most of the time the BT will be in the low power mode.

Thanks, Sreekanth

RE: Interfacing PA with nRF51822

Håkon Alseth — Tue, 17 Nov 2015 09:34:15 GMT

Hi,

PA's have been widely discussed in several threads, for instance this one: devzone.nordicsemi.com/.../

Your second option will most likely not work, as the nRF51 matching network has two jobs:

Differential to single-ended impedance conversion
Heavy filtering.

Having a BALUN that does both of these jobs sufficiently is hard to achieve, and I would recommend that you use our reference layout with either discrete or integrated BALUN option, then connect this to an external single-ended 50 ohm input/output RF PA, such as your first option. You can use the "VDD_PA" pin to control the external RF PA.

Note: The bluetooth core spec for LE devices limits you to sending max. +10 dBm EIRP. This means that you will only gain 6 dB link budget compared to running the nRF51 with +4 dBm output.

Cheers, Håkon