Hi All,

I want to give very precise voltage reference to MCU(STM32F4) Vref+ pin for my measurement.
So could any body explain calculation for me.
Vin = 5V
Vout = 3.3V

R_supply : ?
R_upper : ?
R_lower : ?
Vout : ?

Regards

 

 

I don't understand the IREF = 1mA in the table, as the data sheet only lists a maximum of 0.5μA.

But you obviously didn't use that value in your table calculations, since those values for R1 and R2 seem correct for the low (or zero) value of IREF.

How "very precise" do you need the voltage?

 

I don't understand the IREF = 1mA in the table, as the data sheet only lists a maximum of 0.5μA.

But you obviously didn't use that value in your table calculations, since those values for R1 and R2 seem correct for the low (or zero) value of IREF.

How "very precise" do you need the voltage?

0 5% accuracy . I want .

I gave someheadroon 0.5uA to 1mA.
I took some headroom for these calculation.

 

Hi All,

I want to give very precise voltage reference to MCU(STM32F4) Vref+ pin for my measurement.
So could any body explain calculation for me.
Vin = 5V
Vout = 3.3V

R_supply : ?
R_upper : ?
R_lower : ?
Vout : ?

Regards

Any resistors with a ratio of 0.32 for R1/R2 = 3.3V out