pavel-demin / red-pitaya-notes

Notes on the Red Pitaya Open Source Instrument
http://pavel-demin.github.io/red-pitaya-notes/
MIT License
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Feature Request - TRX-DUO 16Bit ADC #1088

Closed enthru closed 1 year ago

enthru commented 1 year ago

Hello Pavel!

As i understand correctly the main difference between 16bit Red Pitaya and TRX-DUO (chinese clone of 16 bit Red Pitaya, but with 125MHz clock and maybe some other differences) is in different clock frequencies. Can i ask you about possibility to modify FPGA code to be able to use 16bits of data on TRX-DUO?

I've made an attempt trying to use 122.88 clock but ext.clock ("short:ext.clock" ) jumper didn't worked as expected (no result when short, still uses internal clock). So looks like i need to desolder old generator first, but anyway maybe it will be useful for somebody who can't solder new generator (maybe replacing clock is not going to work at all).

pavel-demin commented 1 year ago

The main difference between these two boards for me is the size of the FPGA (XC7Z010 vs XC7Z020) . The XC7Z020 FPGA on the Red Pitaya SDRlab 122-16 board is significantly larger.

The LTC2208 ADC has an SNR of around 78 dB. It corresponds to the effective number of bits of approximately 12.7. I think 14 bits is just enough for this ADC and 2 more bits won't do anything useful.

Anyway, in most projects in this repository, it is enough to change a couple of lines to switch to 16 bits. For example, here are the links to the corresponding lines in the sdr_transceiver_hpsdr project:

https://github.com/pavel-demin/red-pitaya-notes/blob/master/projects/sdr_transceiver_hpsdr/block_design.tcl#L67 https://github.com/pavel-demin/red-pitaya-notes/blob/master/projects/sdr_transceiver_hpsdr/rx.tcl#L145

enthru commented 1 year ago

Got it! Thanks for the info and quick answer.