I'm trying to control an LDO/DC-DC converter externally (using a DAC for example). I was thinking of injecting current into the feedback pin (see the schematic below for illustration), is that a bad idea ? Anything I should be extra careful with ?

I aim to drop the output voltage past the regulator's voltage reference, is there any issue with doing that ?

*The regulator's load, capacitors and voltage source were omitted from the schematic*

![schematic](https://i.stack.imgur.com/Zgnea.png)

[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fZgnea.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)

EDIT:
The ADJ pin might have caused a misunderstanding.

I was referring to regulators which use a constant voltage reference going into the error amp, such as TPS74701:
[![TPS74701 Block Diagram](https://i.stack.imgur.com/RbhEN.png)](https://i.stack.imgur.com/RbhEN.png)