PIC16F versus PIC16LF Parts

[rsocor01]

Hi all,

To the best of my knowledge the only difference between the PIC16F and the PIC16LF is the input power that they can take. Where the PIC16F part can take a higher Vin than the other part. Am I correct on this? Is there any other difference that I should know about?

The issue comes in that I programmed a bunch of PIC16F1939 with a HEX file generated in Microcode Study with a PIC16LF1939 set as the PIC to be programmed. My circuit is working with Vin = 3V, so that the voltage is ok for both chips. The chips PIC16F1939 seem to be working ok, but I'm concerned that the PIC16LF1939 generated HEX file might cause any problems. Any help and comments will be appreciated.

Thank you for your help,

Robert

[prstein]

Hello Robert,

It looks to me that you are correct. I can see no differences beyond the maximum voltage on Vdd and Vcap.

There is no reason the HEX files should be any different. I don't use a lot of 16F parts anymore but I've used 18F and 18LF parts interchangeably.

Best Regards,
Paul

[rsocor01]

Paul,

Thanks. Yes, I haven't had any problems so far when interchanging the 16F and 16LF parts. Still, I'm curious to know why they have a 16LF or 18LF part just to have a smaller Vin range. That just doesn't make any sence, at least to me. Maybe somebody here in the forum knows the answer to that.

Robert

[Charlie]

Obviously the smaller voltage range is less desirable - It's an artifact of using a different silicon technology to achieve additional power savings. If you can live with the 3V range, the LF parts can save you power. If you need 5V, or if you need a part with a better sense of humor about transients, or if minimum power is of lesser consideration, the F parts are the way to go. The actual logical structure, and hence behavior of the devices is identical in my experience, so the same code runs on either.

[timmers]

I've had many problems with EEPROM write errors when using a 16F877 part on 3.3v power (20Mhz crystal). Worked fine at first, then deteriorated over time. Replacing with a LF part cured the problem.

I would re-compile for a LF part if possible. You just never know, and it would reassure me to know I did!

[rsocor01]

Charlie,

That makes a lot of sence. It explains why the LF part is the way to go in some application.

Timmers,

Yes, we just never know.