252 or 2520

[jblackann]

Have you checked Microchip's site? There is a parametric search that you can use that will list all of the different features that each micro has to offer.

[paul borgmeier]

From Microchip website

18F252
Not Recommended for new design
Please consider using device PIC18F2520

If you are not planning to make your device in the future, then either option will work. If you are going to make them in the future, the 18F252 might not be around and you will have to migrate to the 18F2520.

Paul Borgmeier
Salt Lake City, Utah
USA

[Bruce]

I've used the 252 for a long time, and it's nice. The 2520 has a boat-load of problems. You might want to take a look at the latest errata sheet for the 2520 before committing to that one.

If you can live with the problems/work arounds shown in the errata sheet, then go with the 2520. If not, you might want to shop around for a similar 18F series without a 16 page errata sheet..;o}

[dsicon]

Yikes !
bruce
this is pretty scary (errata)
have they respun the chip yet ?
any major issues to note?

the MEL parametic PIC picker is pretty nice

[Bruce]

I'm not sure what silicon revision they're up to yet on this part, but it's worth looking into if you plan on using one. That is indeed a hefty bug list for the 2520.

[Melanie]

I use the smaller RAM 2420 extensively without any issues. Admittedly, I'm not using anything over the ADC's and PWM modules (and all the other pins as Digital I/O) but they all work flawlessly. And I've almost maxed out the Program Codespace and PBP handles it all just perfect.

The big advantage of the 2420 over the 242 (2520 over 252) is on-board handling of MCLR and Internal Oscillator. This means you have 25 usable I/O pins on the 28-pin package...

[dsicon]

thanks melanie for the encouragement
some of the errata applies to the I2C
have you used that ?

a quick scan of the errata sheet shows that the bugs
seem to apply equally to the 2420 and 2520

considering that the price is pretty close i always wondered why
they bothered with both sizes of memory

have you had or heard of any reports of strange field falures?
i have heard one, not sure how trustworthy or relevant it is
ds