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Old July 22nd 09, 07:02 PM posted to rec.radio.amateur.homebrew
SpamHog SpamHog is offline
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First recorded activity by RadioBanter: Sep 2006
Posts: 39
Default Did anybody use the Si4735 quasi-SDR-SOC in a HB receiver?

"The Si473x, Si474x and Si4707 devices are the industry's first fully
integrated, 100% CMOS AM/FM/SW/LW and WB radio receiver ICs. Offering
unmatched integration and PCB space savings, the Si47xx only requires
two external components and less than 15 mm˛ of board area excluding
the antenna inputs."

In chippic language, this thing has PGA, DSP, ADC, DAC. While there's
a PGA block that seems non-FP, the DSP is upgradeable - hence
reconfigurable, although I bet the code is closed and well guarded.

In radio language it implements 2x AGCed LNA, 4x balanced mixer, 2x I/
Q detectors, DSP demodulation, RDS/RMBS, both digital and analog audio
out (stereo of course).

https://www.silabs.com/products/audi...s/default.aspx

https://www.silabs.com/products/audi.../Si473435.aspx

The application notes document for antenna selection and layout is not
to be found on the Silicon Labs website, is still under NDA but a
version for a shortwaveless version has leaked from Russia.
http://delanet.ru/images/stories/pdf/AN383_si4711.pdf

Several chips in the that family have transmit capabilities too,
complete with varicap antenna tuner.

A quasi-SDR-SOC, taking up less room than a small knob.