Vref current required - stm32f103vct6

RnnKrk · ‎2018-03-15

Posted on March 15, 2018 at 22:49

Hello,

I will use this Cortex with both ADC and both DAC active.

The datasheet says the maximum (wort case) current required into Vref is:

220 uA for ADC and 220 uA for DAC.

I am going to apply the separate Vref with a shunt reference hence I need to calculate the pullup resistor. So I must know what is the maximum (worst case) current I must provide for Vref pin.

Is it 2x for ADC + 2x for DAC = 880 uA ?

Or less (as buffered inside the chip) ?

Or even more as the max current for DAC in the datasheet is for 'Standby mode, no load'. So should I increase the total Vref current still more (for Run mode and some load) ?

Thank you for any help.

Best regards

Robert

T J · ‎2018-03-16

Posted on March 16, 2018 at 08:22

' The datasheet says the maximum (worst case) current required into Vref is 220 uA for ADC and 220 uA for DAC'

I think they are saying the minimum required to satisfy the internal circuits is 440uA in the worst case.

It could be lower on some batches but not always.