Using VIN for a cpu fan

[MIke Vine]

tl;dr: If I use a 12v external power supply on my Arty-S7-50RevE can I use VIN (& GND) to power a 0.1A, 12v cpu fan?

Longer: I'm having heat issues with my soft CPU on the S7 and so want to cool it before I take it multi-core. I've installed a heatsink (from here http://uk.farnell.com/fischer-elektronik/ick-s-14-x-14-x-10/led-heatsink-with-pins-square/dp/1850054).

I've got a nice CPU fan left over from another project which fits my arty project well. However the fan is 12v.

But I'm already powering the board with a external coaxial 5A 12v supply. Looking at the manual you can also power it via VIN (J8-8) instead - and if you look at the diagram VIN is just connected straight to the v-external power supply*. This seems to mean I should be able to treat VIN as a 12V output and directly connect the 12v cpu fan to it.

Is this something which is acceptable? (I tried it and it seems to work fine)

thanks

mike

* see Figure 1.1 here: https://reference.digilentinc.com/reference/programmable-logic/arty-s7/reference-manual

[BogdanVanca]

Hello @MIke Vine,

Please check this link on page 9 https://reference.digilentinc.com/_media/reference/programmable-logic/zybo-z7/zybo_z7_sch-public.pdf. The VCC5V0_FAN voltage it's "created" from the VCC5V0 voltage supply that is passed trough a noise filter circuit, made from a zener diode (CDBU0130L) and a capacitor (C250). The fan will work fine, but you need to get sure that you don't introduce noises on your power supplies rails. So, in my opinion a simple noise filter that could "isolate" your fan from the rest of the circuits would be helpful. 

Best Regards,

Bogdan Vanca