Lpc2000

Hello John,

My 2 cents:

> Now my question, should the MCU boot up when you power up 
> from negative VCC as little 
> as -0.5V? 

Can this cause a different power-up sequence for the 3.3V and 1.8V
supplies (I guess the "-0.5V" is nominally 3.3V) ? Meaning:
- in the "normal" case, 3.3V rises before 1.8V,
- in the "abnormal" case, 3.3V lags a bit, and 1.8V appears first.
You will probably need to have acces to digital scope to check that.

Sorry if you have already checked, or if this is clearly part of the
data sheet, our project has not started yet, and I only have general
ideas  at this moment.


> Should a reset chip (I'm using TPS3836 3.3) help? 
> In my case, it doesn't. Thanks.

Just a thought here: I feel using a 3.3V reset device on a nominal 3.3V
supply is too tight. If on the board you use, "3.3V" is really 3.30V
nominal, of course. I would expect problems with glitches, aging &
temperature drifts. Unless your application warrants otherwise, I would
recommend a 3.0V reset device.

Hope this helps

Etienne