PIC16F722 and 722A

rovtech · Joined: 24 Sep 2006 Posts: 262

Sorry for asking here, Microchip Forum is useless and keeps sending me in circles.
I was using 16F722-E/SP, now I find DigiKey says they are non stock and have 16F722-I/SP and 16F722A-I/SP
What is the difference?

newguy · Joined: 24 Jun 2004 Posts: 1907

-E means extended temperature range, -40C to +125C. -I means industrial temperature range, -40C to +85C. Readily available from the data sheet.

If you're asking what the difference is between the '722A and '722, consult the data sheet or www.microchip.com.

rovtech · Joined: 24 Sep 2006 Posts: 262

Thanks Newguy.
All I could find on the Microchip site (comparison) was that the 722A is recommended for new equipment. There does not seem to be a difference apart from the A version is about 40 cents cheaper on Digikey.
So the extended version is obsolete and the A is no better but cheaper?
I'm not about to compare hundreds of pages of data sheets line by line.
Comparing the Errata sheets it seems the 722A has corrected most of the problems. Why wouldn't they say that on the first page of the data sheet, of at the top of the "Comparison" chart?
I guess I'm just lazy and hoped someone here could save me an hour of searching. Yesterday i could not even get into the Microchip site.

newguy · Joined: 24 Jun 2004 Posts: 1907

Usually an "A" part is just a 2nd revision of the original. They frequently make improvements and tend to fix a lot of errata issues.

Years ago the PIC16F877 was a go-to for me. Then along came the 877A (for cheaper too). That became my go-to. It just worked. The only differences that may bite you are electrical performance issues like the oscillator and whether it can be run at a similar frequency at a similar Vdd level. That sort of thing.

Ttelmah · Joined: 11 Mar 2010 Posts: 19504

and the key on temperature ranges is that you need to use what your
product must have. If you are building something to go into a car for
example, then the -E temperature range is required. Temperatures
behind the dash panel, can easily get up to around 100C. However
for 99% of locations the -I is totally adequate.

rovtech · Joined: 24 Sep 2006 Posts: 262

One drawback of the 722 is that it cannot be used as a Master I2C.
Since I use I2C extensively I had to look for other chips but ran into problems after checking the Errata. I finally settled on the 16F1938 family.
My advice to any novice reading this is to always read the Errata first then breadboard and check critical features (I2C) before committing.

Ttelmah · Joined: 11 Mar 2010 Posts: 19504

It can of course do master, using software I2C. This is not that much slower
than hardware. Where hardware is essential is for a slave.