[SOLVED] Programmable power supply in PICKIT programmator

[biedronka]

Hi guys,
I'm doing some project and I'm about to use PICKIT 2 or 3 programmator for the first time ( I began exploring specifications of both). Does anyone has any experience in using this kind of programmator because I'm interested if it's possible to change its power supply voltage and if it is, how. I'm asking this because I'm using also a microcontroller which is powered via 3.3 V power supply and by some requests I got programmator should be powered the same. Thanks in advance!

 

[InsAndOuts]

Let's first clarify the power supplies during programming:
The PICKIT is powered from the USB supply, not from the circuit.
During programming, your microcontroller can be supplied from the system supply. It could also be supplied from the PICKIT, as long as the target consumes < 30 mA. Refer to the PICKIT user guide page 70.

In the standard software from Microchip (IPE), you can set voltage levels from 2.375V to 5.5V in steps of 125 mV. This adjusts the logic levels as well.

Two 'bonus' remarks/warnings:
- AFAIK the Pickit 3 is obsolete, so you might want to start with the pickit 4 or something else. The power situation is different there.
- When using system supplies during programming, be aware that the programmer GND may be on protective earth level, depending on how your laptop/pc is earthed. If you don't understand the implications, it's better to make sure you do before connecting it to your hardware.

 

[betwixt]

Genuine PICKIT3 has a programmable VDD generator on board but most of the clones do not. If you are thinking of building your own from a schematic on the Internet, make sure its one that includes the variable supply.

Brian.

 

[biedronka]

Genuine PICKIT3 has a programmable VDD generator on board but most of the clones do not. If you are thinking of building your own from a schematic on the Internet, make sure its one that includes the variable supply.

Brian.

Yeah, I wasn't precise enough, I was definitely thinking about programmable VDD voltage. It confused me a bit how is it possible to programme 3.3V PIC with 5 V programmator, without damages. I read this site a bit first : https://components101.com/misc/pickit3-programmer-debugger-pinout-connections-datasheet, there's a table with pin description, and mentioned VDD target voltage (3.3 V or 5 V). Later, I read in an user guide for PICKIT 3 from Microchip that it has increased VDD and VPP voltage range. I must provide 3.3 V for my uC and I wanted to know if connecting PICKIT VDD to 3.3 V is also OK and necessary.

Fortunately, I will be able to use PICKIT2 or PICKIT3, but I'm about to try with version 3.

 

[betwixt]

You can connect a programmable VDD (set to 3.3V) to the VDD of the PIC OR you can turn VDD off in the PICKKIt and use the supply on the board, its a software configuration option. Note that if you are programming in-circuit and you enable VDD from the PICKIT it will also power up everything else sharing the same VDD connection so be aware of its current limitations.

Brian.

 

[biedronka]

You can connect a programmable VDD (set to 3.3V) to the VDD of the PIC OR you can turn VDD off in the PICKKIt and use the supply on the board, its a software configuration option. Note that if you are programming in-circuit and you enable VDD from the PICKIT it will also power up everything else sharing the same VDD connection so be aware of its current limitations.

Brian.

Thank you Brian, I'll keep that in mind!