R820T2 Register Description Data Sheet Now Available

Recently Luigi Tarenga wanted to do some work on developing RTL-SDR drivers, so he emailed Rafael Micro requesting some additional documentation about the chip. Usually previous requests to Rafael Micro for such information seem to have gone unanswered, but this time it seems they have decided to publicly released the Register description document for the R820T2 chip.

Previously the R820T datasheet was leaked/released to the public, but the information in the datasheet did not help much with driver development. This register description document describes the function and configuration bits for the registers on the chip, and may be useful for people wanting to develop better drivers for the RTL-SDR.

We have uploaded a copy on our server here.

Description of some of the registers in the R820T2 chip.
Description of some of the registers in the R820T2 chip.
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Unfortunately the band selection filter doesn’t work (at least for me).

BTW (shameless plug) if you are on linux, you can try this: https://github.com/gat3way/r820tweak it would allow you to tweak some of the settings while waiting for driver/sdr software updates.


Thanks! I use gqrx a lot!


I’m pretty sure that airspy team already havr this level of details. Also they did some work of engineering so this is just basic level. This document can speed up code review, bug hunting and experimenting with rtlsdr in general


does this affect only the rtl-sdr or can there be a enhancement done for the airspys too ?


I’m 99% sure that the people behind the Airspy have, long ago, signed an NDA with Rafael Micro to gain access to the documentation. But access to documents without an NDA can only be a good thing.


Airspy is already very well optimized and the driver is open source. Now we can understand what exactly they did in order to match the R820T2 with their 12bit ADC.


It seems it comes with a built-in selectable band filter on RF front-end, is it correct?


R26 seems to have a high- medium- low band filter. I am not sure what the ranges are. I would guess something like VHF, UHF low, UHF high maybe. But that is just speculation.

Hopefully this release will lead to new and better drivers!

DB Gain

And perhaps some power savings.