What is the function this united Ds instead of a D

[abdulbadii]

What is the component function has united two Ds, it's seen used just to function a D rectifying from the 2 || pins at right to output at left
No real image, just it looks like Fet transistor

is there a necessary function else than such, so it's favored to be produced as a integrated component?

 

[danadak]

Note normally used to seeing them connects as :

Without a total schematic not easy to answer your question.

If connected to a I/O pin of a cmos part its normally to insure pin
never violates Vdd >= Vpin >= Vss. To insure no significant current
flows thru onchip parasitic diodes which can cause CMOS latchup.

https://www.ti.com/lit/an/slya014a/slya014a.pdf

Regards, Dana.

 

[Papabravo]

Is this symbol connected with a real part?
Not sure what you mean by a "FET transistor". Did you just make that term up? Literally it means "Field Effect Transistor Transistor".

 

[Diver300]

Simple components like diodes are sometimes made with more than one component in a package. It's saves a bit of cost, board space and assembly time over having two separate diodes.

Here is an example:- https://www.diodes.com/assets/Datasheets/ds30234.pdf

There are versions that are common anode, common cathode and series.