Re: Si570 Phase Noise
> I have uploaded data supplied to me by Silicon Laboratories comparingHi Bill,
> the phase noise of the CMOS and LVDS versions of the Si570 to the files
Thanks much for the phase noise data. Looks like the CMOS version is
working excellent as suspected from initial testing when the device
was first available.
My phase noise testing was at much lower freq. (approx 9MHz) and
slightly better (most likely due to the larger dividers in the chain).
I was showing around -135dBc/Hz for the LVDS and -130dBc/Hz for the
CMOS version. This was using my limited test equipment and crystal
BPF. This testing approach is described in detail in the latest
(Jul/Aug 2008) issue of QEX for those interested.
Great to see that the measured data is tracking the LVDS info in the
data sheet. In my view they should be proud to also publish the CMOS
This sure confirms why this chip has become so popular. Both versions
look excellent and nice to have the choice.
73, Mike Collins KF4BQ
- IR thermometer through the oven glass? No way that will work. You will mostly be reading the temperature of the glass on the outside, which is fairly opaque to long wave IR used by the thermometer. Better off using an oven thermometer or a thermocouple probe of some sort.
IR thermometer should work well for hot plate though.
Josh Massie wrote:
I once tried two different digital IR thermometers from Harbor Freight Sales.Â But the readings were not reliable from a PC board being soldered in my toaster oven.Â So I abandoned that idea. Bill WA9PWR
Same results for me, you could not trust the reading, I also wondered about how transparent to IR was the ovens
window. I don't know much about thermal properties of materials, but I use a thermal imaging camera in my day (and night) job, and you can't use it to see through glass. Our cameras use Germanium lenses for this very reason. Things like windows appear as mirrors through the camera. I imagine that you might be able to read the heat content of the surface of the glass, but not through it. How closely correlated those two points are I have no idea. Josh NF6S