I have a circuit using LD39015 1.2V Low Drop-out voltage regulator.
The value of VCC is 3.3 Volts. The goal is to supply an ADC channel with a constant stable voltage so I can use that to reverse calculate the VCC. And yes I have looked at both Vref IC and Vreg IC options. But while testing the Volt Reg option, I am seeing a 1.189 volts at the output of the voltage regulator with R2 = 10k, 1.191 V for a R2 = 1k and 1.11V for R2 = 100k Ohm. First of all why am I not getting exact 1.2V rated output from the regulator given it satisfies the min input voltage and the dropout voltage. Secondly how does changing the resistance value change the output of the regulator even when the voltage regulator gets sufficient input voltage. Thanks.