mEZDPD3603A strange power readings

I am currently trying to program the mEZDPD3603A with Virtual Bench Pro 3.0.

I have an input voltage of 12V and I want to get an output voltage of 3.3V.
With the support on this forum I found out that I need to set the Vref to 0.66 and the FB to 1/5 as Vout = Vref/FB . However this yields an output voltage of 2.8V
I determined to problem to be that when I set FB as 1/5 I acutally obtain an FB of 1/4.3
So if I set Vref accordingly to 0.77V I get the desired output voltage of 3.3V.
However I find this strange and would like to know why that is the case.
Also if I measure my VCC I get 4.64V and the manual states that VCC should be 5V

I already tried driving EN high with 3.8V and also just leaving it open, then I can measure roughly 10V on the EN pin. When I drive the PG and FT high they also stay high with 5k ohm resistor, connected to 3.8V

My multimeter is definitely working, I tested it on various other sources.

Any idea whats wrong ?

Hello dlayh,

Could you let me know what suffix code you are using for your mEZ device?

We have suffix code that gives 3.3V default:

Regards,
Vinh Tran

Hello Vinh,

I am not sure how to find out, I bought it from Mouser
(https://eu.mouser.com/ProductDetail/Monolithic-Power-Systems-MPS/MEZDPD3603A?qs=byeeYqUIh0MwKeDG8At29w%3D%3D&countrycode=DE&currencycode=EUR)

But when I first tested it I had an output voltage of 4.3V which I think should mean that I have the suffix 0001. This was with Vref of 1V and an FB = 1/5

Cheers
Dennis