alt.engineering.electrical

Joel Kolstad wrote:

> "Joerg" wrote in message
> news: $ @ ...
>
>>If it doesn't have to be right now.
>
>
> No, it's not right now... just starting to think about an upcoming project
> which appears to be about 90% of a sure-thing at this point.
>

Good. Many of the calls I get are like "Well, the roof is already on
fire...".

>
>>Did you guys consider using the receive section in chips like this one?
>
>
> I haven't looked at that one before; thanks for the link. (Some of the
> low-power parts that we've used in the past were aimed at, ., paging
> applications and unfortunately are now gone.)
>

Yes, pagers are almost gone except for emergency crews. Even if the
chips weren't gone I would not bank on them for anything that needs to
remain in production for years. And from experience I'd try to stick to
mainstream manufacturers and be careful with recently sold or acquired
companies or product lines. Sometimes those parts can do a quick Houdini.

Take a look at chips for higher-end keyless entry systems. Meaning the
ones that really work, not the super-cheap super-regen receivers.

>
>>20mW will be a challenge at 900MHz though, even with this chip. Would
>>auto-polling be possible in your application or is it pretty much a
>>continuous data stream?
>
>
> It sleeps for awhile, wakes up to listen every now and again, and repeats.
> (It initially has to listen for awhile to "sync up" and then, knowing it's own
> ID, can figure out when to sleep and when to listen.)
>

If your 20mW spec is for the average consumption that should be no
problem. If it is for the active phase it'll present a bit of a
challenge at 900MHz. But I guess challenges are why guys like us chose
engineering.

--
Regards, Joerg