I would like to create a 16 bit DAC in STM32F103RET6. But STM32F103RET6 only has 12 bit DAC. How do I implement a higher resolution DAC in STM32F103RET6? Thank you. Please see the file AN64275 in google
You either connect an external ADC. Or you show your skills in analog design and implement a solution where you add an external offset voltage to the input signal and then through multi-sampling produce these additional bits of resolution.
Obviously, additional bits of resolution doesn't mean additional bits of precision - you still need to take into account the linearity etc of the ADC, stability and precision of the voltage reference and any additional noise your design introduces besides the intentional offset voltage.
I think it is a DAC he is talking about and not a ADC
And with a DAC the issue is to modulate the output with a low-pass filter. So similar strategy. If the DAC toggles 50% of the time between two values, then the low-pass-filtered value will be an intermediate value similar to an extra bit of resolution - but with a loss of output bandwidth.
Trying to add 4 additional bits obviously adds the issue of stability of that low-pass-filtering to the issue - digital noise on the ground plane might represent several bits of the intended output resolution.