Admittedly, this is going to be a challenge to answer since it appears what I'm doing is against the specification... but here it goes... hopefully someone at ST knows...
Are most folks using these radios only in battery applications? I ask because the S2-LP SDK ends up *not* enabling the SMPS by default. I've verified this with a scope at the SMPS pins, a full radio register dump after calling to RadioInit(), as well as code inspection where nothing is calling RadioSetExternalSmpsMode(S_ENABLE).
I only just noticed this and it's contrary to my layout which is in accordance with the SMPS-enabled circuit.
This combination ends up putting 0V on SMPS1 and SMPS2 (because of the bypass caps) and 3.3v at VDD_SMPS.
I assume having 0v on the SMPS pins has an adverse effect on TX. But I'm not transmitting so I don't care.
Does having 0v on SMPS affect RX sensitivity?
Thanks for your insights.
