Kindly refer to the schematic snapshot below for ADP2119ACPZ-1.2-R7.
We are getting 0.6V at the output of this regulator at inductor L1 even though this is a fixed output voltage regulator. The branding of LFK printed at the regulator confirms that it is ADP2119ACPZ-1.2-R7.
However when I mount 10K resistor at both R10 & R12 of ADP2119ACPZ-1.2-R7, the output comes as desired as 1.2V as per below formula for adjustable output version.
Since this is a fixed output regulator rather adjustable version, why do we need to mount both RTOP & RBOTTOM at this regulator. Ideal case should be as per above circuit diagram.
I am also using ADP2119ACPZ-1.8-R7 in the same board, and it gives correct output as desired with RTOP = 0E & RBOTTOM = DNM as shown in schematic below:
What is the reason of this misbehavior of ADP2119ACPZ-1.2-R7?
Kindly note that both these ICs were procured as free sample from ADI Website for our prototype development.