Hi David,
Could you elaborate why do you consider this approach? While we see
some
advantages of it in terms of lower noise, it looks like our approach
is few times
cheaper with reasonable noise and stability figure. If we
understood correctly,
bare VCTCXO chip costs $230 on DigiKey, while in our case discrete
unit with
all accessories produced in low volume costs about $100.
On Mon, Sep 28, 2009 at 22:06, David Burgess
<address@hidden> wrote:
One of the approaches we are considering for OpenBTS is to use a
VCTCXO with
the control voltage taken from one of the D/A outputs of the FPGA,
with LOTS
of low-pass filtering, of course.
This would not give a wide range of frequencies, but would allow
precise
frequency calibration through the existing libusrp APIs.
On Sep 28, 2009, at 9:00 AM, Tim Pearce wrote:
In terms of integrating more tightly with the USRP/GnuRadio
You could (maybe) just use the SPI pins and one of the digital IO
lines as
the enable (the ATMega8 running as a slave)
That way theres functions to communicate with the chip already
built in you
just need to define the various commands etc?
Tim.
David A. Burgess
Kestrel Signal Processing, Inc.
--
Regards,
Alexander Chemeris.
SIPez LLC.
SIP VoIP, IM and Presence Consulting
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