STM32 DAC buffer

[kender]

Folks,

I have two questions about the buffer. I suspect that these questions may be related to each-other. I wonder what’s your hands-on experience with the STM32 DACs.

Q1. The datasheet (p.96) mentions that the minimum DAC output voltage V_DAC_OUT is 0.2 V when the buffer is enabled. That means that the output of the buffer isn’t rail-to-rail. Could somebody confirm this, please?

Q2. Does the buffer have an accurate output without any load? Or, does it require a minimum load? The datasheet mention that the smallest resistance that the DAC can drive without distortion is 5kΩ . I didn’t spot any mention of the minimum load in the datasheet or app notes.

I can work with an unbuffered DAC no problem. I just want to have a better understanding of the STM32 DAC and vicinity.

- Nick

 

[FvM]

I read the minimal load resistor spec so that it guarantees 0.2 V margin. Margin with higher load resistance might be smaller but isn't specified.

By nature of a buffer, it works between minimal and infinite load resistance.