Does VPP really has to be 13V?

[Futterama]

Hello there,

Everywhere I look, people talk about VPP being 13V or 12V (I have used 12V with success) but in the "FLASH Memory Programming Specification" for PIC16F628A and PIC16F88 (and probably many others) the "High voltage on MCLR and RA4/T0CKI for Program mode entry" (VIHH) is from VDD + 3.5 to 13.5V.

If I use VDD = 5V, then I could actually use 8.5V (or 9V to be sure) as VPP? Or am I mistaken here?

I was just thinking, is it really necessary with 12V? It would make things easier for me to construct a programmer circuit if 11.3V is enough.

Regards,
Futterama

[Melanie]

The Microchip specification for VHHR is Vdd+3.5v as minimum, with 13.5v as maximum BUT it varies from PIC family to PIC family. Some have a 10v minimum and 12v maximum. You must refer to the Programming Specifications for the PICs you want to use... also check here...

http://www.microchip.com/stellent/id...GE&nodeId=1407

[Futterama]

Thanks for the link :-)

So the basic answer to my question is "yes, but it depends on the specific PIC", right?

I only want to program a series of specific PIC's, so I could check out all the programming specifications for them, and see if they have the same spec as 16F628 and 16F88.

Regards,
Futterama