How do I connect a 0-10V analog input to MCU with high input impedance?

^{simulate this circuit – Schematic created using CircuitLab}

The way I do this is by taking the voltage you want to measure with the ADC, and voltage divide it down so that the maximum voltage is slightly less than your MCU supply voltage which in this case is 3.3v. In this case it works out to be around 3.2v if the signal is the maximum 10v. Then you run it though the voltage follower to the MCU. D1 and D2 are optional and protect the MCU pin if the voltage on the output of the opamp were to rise above or below the power rails. R3 is also optional and is used as current limiting resistor. When combined with the internal sampling capacitor of the ADC, it also creates a small RC filter. Just make sure not to increase resistance for R3 too high, or you will defeat the purpose of the voltage follower.

THe LM358 has an input impedance ~ 10M and output impedance ~ 1k @ 1V/1mA and 100mV /50uA ~2k so it is does not reach negative rail to 0V. But perhaps close enough if your load is < 50uA or >> 2k. That is due to saturation of BJT’s.

Consider matching input R to V+,V- to null input bias current induced Vio with ~1M on each input.

Consider output current with voltage divider R’s with <1V = Vout. Raise the output R’s to reduce Iout. The clamp current from MCU diodes will limit the output voltage without a need for a Zener to << 1mA.

This ought to reduce open cct Vio and Vout .

A better solution might be to use a RRIO CMOS OpAmp with 10M on each input.