Do GPS modules with embedded RTC crystals have more noise?

0 votes
Hello, I know RTC crystals are needed for faster TTFF and in on-off power save mode. But I know also they're one of the most severe sources of noise so I was thinking of using modules that don't have them. Any thoughts?
by maryammagdy asked Dec 3, 2018
34 views
Please explain more about what you heard about RTC crystals:  what kind of noise,.... thermal noise, acoustic noise, radiated RF noise? Or do you mean they are sensitive to external noise, or act as a microphone?
0 votes
RTC crystals are used everywhere.  Their role in timekeeping is necessary and rock solid in a good design and implementation.  They are sensitive to acoustic noise but that has little effect on timekeeping.  The RTC oscillator does not usualy generate RF noise that interferes with GNSS unless the design ior implementation are really bad.
I can think of no reason to avoid use of an RTC crystal except to save a few cents and losing a key function of "hot start".
by grampy answered Dec 3, 2018
by grampy edited Dec 10, 2018
The peak-to-peak voltages, slow edges, and energies involved, are all rather low for RTC crystals, and not in-band for anything GPS/GNSS related.
I'd be interested in understanding the "severe" cases the OP is referring too.
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