DAC peripheral on STM32F407

[gowtham K]

I am working with STM32F407VG microcontroller (STM32F4 discovery board). When using the DAC peripheral for an application I was verifying the minimum and maximum voltage that can be generated from the DAC pin by providing values of 0 and 4095.

However the minimum and maximum should be within VSSA and VDDA even in case of VREF+ given to VDDA.

But when setting the DAC value to 0, I receive 50mV on the scale of 0 - 2.9 V and 61mV on the scale of 0 - 3.26V.

As per my understanding I thought I should be getting 0-1mV when DAC value is set to 0.

I have no other peripheral initialized or connected any other board to discovery board.

Can someone please tell me reason for its behaviour?

[waclawek.jan]

The DAC has limitations when you approach the upper and lower end, depending on whether you have buffering switched on or not.

Look at the relevant chapter in the Electrical parameters in the datasheet.

JW