Pmod AD1 External Power

[hkhajanchi]

Hello everyone, 

I am currently working on a project which requires me to control a tank system using a Nexys 4 DDR FPGA and a PMOD AD1 and PMOD DA2. The analog sensors of the system can output up to 4.8 volts, and I wanted to feed that into the AD1 directly without the use of a divider circuit. I was wondering if it was possible to externally power the AD1 using the VDD port so that it can read up to 5V. I might be mistaken, but in reading the technical specifications I saw that the A/D in the AD1 can read voltages up to the voltage that is supplied externally. 

Thank you for the help!

[jpeyron]

Hi @hkhajanchi,

Powering the Pmod DA1 with an external 5v will allow you to take in analog voltages up to 5v.  This will also make the digital logic 5v which is above the 3v3 maximum voltage input on the Pmod Ports of the Nexys 4 DDR.  In this case you could use something like the Pmod LVLSHFT here for just the data side to bring the digital logic down to 3v3.  You will have to make sure the grounds are connected correctly as well.

cheers,

Jon