Driving several chips with a single oscillator

So long as it is the same frequency, or multiple thereof, why would you think it is not possible? Am I missing something?

Tam

new PCB where size and weight are critical. I would

I'm wondering if the input capacitance of the chips affects the oscillator. The oscillator has an optimal load capacitance that it performs with. I can't seem to find the input capacitance information in the datasheets of the dsPIC or the BT module.

Sure, but make sure that both chips get clean, fast edges, which means that you've got to handle the trace routing, impedances, and terminations properly. Even cheap XOs can have sub-ns risetimes these days, and lots of cmos chips have very tender clock inputs. A little ringing, or a half-level plateau and a bit of crosstalk, can cause serious grief.

John

new PCB where size and weight are critical. I would

That information should be there, buried in the 100s of pages of other necessary information.

By the same token, though, if you can't be sure that two will work, how can you be sure than one will?

If the oscillator has a logic level output, it will work with any load within its fanout limits. If you are using the oscillator built into one of the chips, and you want to use its output to drive the other chip, I would put a gate of some kind near the source chip to buffer the output.

Tam

new PCB where size and weight are critical. I would

use a couple of unity gain stages to drive and semi isolate them.