Yahoo Groups archive

Lpc2000

Index last updated: 2026-04-28 23:31 UTC

Message

Re: [lpc2000] Re: Flash Utility Hell..

2004-05-07 by microbit

> > It really depends on the Xtal, rather than the clock oscillator
> itself.
>
>
> [deleted]
>
> Philips actually recommends using larger value capacitors, there is a
> table in the user manual on page 39 that suggests values of 58 pF for
> a 30 pF crystal load capacitance and Rs < 50R.
>
> Leon
I see a table with recommended caps for various load cap. crystals (10, 20, 30 pF),
but no recommendation to use _large_ caps ?
I didn't mean to contradict you Leon, just that Xtal oscillators are very little understood
beasties at times, and many just bang it in without knowing their actual load capacitance,
but considering it is the heart of any MCU system, it should be given MUCH more attention.....
(regarding runtime reliability). Notwithstanding layout issues...
I hope the brief before clarfied it a little.
Mayge Philips_apps could clarify whether the oscillator indeed is a Pierce, and whether it's
a NOT gate or a FET ???
This will help in future.
B rgds
Kris

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.