Tool/software:
The datasheet recommends the value of (R1+R2) should be 10k-100k to avoid divider error, but there is no specification on minimum current required for the FB input.
What is the minimum FB pin input current required for Vout = Vfb(1+R1/R2) to be valid?
Hi Timothy,
FB input current is typically in the range of 10nA-100nA. The 100kΩ maximum divider resistance is given to limit the worst-case error due to the feedback current to less than 1%.
The feedback current-induced error is
For a feedback pin current of 100nA and total divider resistance of 100kΩ, the error looks like this as a function of output setpoint:
Best Regards,
Alex Davis
