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Pickit 2 programing a PIC at 5v with 3.3v chips on board

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Veramacor:
Hello all again,

I have a PIC16F886 that can be run at 3.3v or 5v no problem.   From what I've read the Pickit 2 programs at 5v.

The problem I'm concerned with is on my PCB there are 3.3v chips (bluetooth module, real time clock).

I would like to program the chip via ICSP (I have the 5 pins already traced).   Does anyone know if the PIC16F886 can be programmed by the Pickit2  at 3.3v? 

The pic is a surface mount type so I can't just pull the chip and program externally.

I can run the normal power source and have the pickit2 not provide power, but the power to the PIC16F886 from the source is only 3.3v and seems not to read the PIC.

Any suggestions?

dimlow:
If your board has its own power, the Pickit 2 will not power the pic. so your safe there. Also in MBLAB you can set the voltage that the pickit will use. That's in the programmer.Setting menu. But there is a problem here if you have a knock off pickit 2. Some of these only use 5v even if you set the thing to 3v.

EEVblog:
The PICkit 2 and 3 program using whatever voltage is read from your device under test, so both are fully compatible with your 3.3V circuit. The PICkit reads the voltage used on your board.
Both PICkit's can also output a user defined voltage on that same power in order to power your circuit.

Dave.

Jon Chandler:
I can't attest to this fact, but I'm told if you let the PICkit 2 automatically detect the device type, it defaults to 5v, and switches to 3.3v only after identifying the part as low voltage.

This brief application of 5v to a 3.3v part may not kill it, but still it's outside the absolute max ratings.  I inadvertently powered a 3.3v 18F25K20 from 5 volts yesterday when I connected a 5v UART-USB adapter and it didn't seem to suffer any ill effects even being powered that way for half-an-hour until I realized my mistake - I think I'll reserve that part for living on the dev board on my desk just in case.


Jon


Veramacor:
Well, its time to buy the real thing -  I've got a knock-off pickit2 device and that is what is most likely happening - Defaulting to 5v only.

Thanks for the tips - exactly what I needed to know!

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