The C8051F300 also has a built-in temperature sensor and ADC, so you could probably implement temperature compensation without any additional component if needed.
On Sat, Nov 2, 2013 at 8:37 AM, Didier Juges <shali...@gmail.com> wrote: > I have actually used these chips at 125C and the factory even gave me > extensive data supporting even higher temperature operation (for missile > applications,m can't tell you more). Don't know about 150C though. That is > pretty high. > > > > On Sat, Nov 2, 2013 at 8:36 AM, Didier Juges <shali...@gmail.com> wrote: > >> It all depends on how accurate the frequency has to be. If you only need >> 2%, I would use a C8051F300 microcontroller's built-in oscillator (24.5MHz >> +/-2%) and divide it down using the processor itself. >> The chip comes in a 11 pin QFN that is 3x3 mm, a little bigger than you >> need, but it does not require any external component. >> The frequency can be trimmed to better than 2% on many Silabs chips but I >> am not 100% sure that is the case on this one. >> >> >> >> On Fri, Nov 1, 2013 at 11:30 AM, Dan Kemppainen >> <d...@irtelemetrics.com>wrote: >> >>> Hi all, >>> >>> I've got a project upcoming that will require a frequency of 32.768 Khz >>> in a harsh environment (Imagine a thousand G's at 100Hz with 150 Deg C >>> temperatures). Also, this thing needs to be small, 2mmx1.5x1.5mm or so. >>> It also has to be low power. Frequency stability is probably less of a >>> concern than just surviving (some frequency error vs. temp can be >>> trimmed out with other smarts in the design. >>> >>> >>> In the past, crystals just haven't liked surviving due to the >>> construction. Have had good luck with ceramic resonators at higher >>> frequencies (50Mhz and up). I've also looked at silicon oscillators, >>> which will work in the application, however with the chip and associated >>> resistors/caps they get a little bigger that what I was hoping for. >>> >>> Is anyone aware of a frequency source (crystal/resonator or other) in a >>> small package that is robustly mounted? >>> >>> Or are there any ceramic resonators available that are in small packages >>> in those low frequencies? I checked the big distributors, and did not >>> have any luck. >>> >>> >>> Dan >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.