AnsweredAssumed Answered

Minimum DAC output Voltage on stm32f30x

Question asked by Simon Schulz on Jun 17, 2017
Latest reply on Jun 19, 2017 by wolff.roger

Hello,

 

What is the minimal voltage the DAC can output?

When I read the Datasheet for the stm32f301 I can see a min of 0.2V with buffer ON.

However when the buffer is OFF the manual says 0.5mV.

 

I use the DAC internally as input for the comparator. When I set the DAC to 0x0000 I can read ~50mV on the output pin.

If I plot a linear ramp I get the first beginning from 50mV up to ~150mV very slow rising and then from there to VCC with the normal and linear slope.

 

Why is that? Why does the DAC only give me a minimum voltage of 50mV and not 0mV? Why is the first part of the ramp with a different slope?

I tested a stm32f301 on my custom PCB and also the STM32F303 on the stm32f3 discovery.

 

Any hints?

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