Hello,There is a component I bought which under microscope looks like the photo below.
How can I know the pin order in this chip?
Thanks.

https://www.digikey.co.uk/en/produc...TCBcDaIPYDsDOBTAtgSwAQDEAiAygGwDMA7AKwgC6AvkA

 

There should be some kind of dot near pin 1 or a notch on the side to the left of pin one.

Post a photo if the actual chip.

 

there are different ways to determine that (moon, dot, bevel, text):

 

In most cases moon is only on one side. if not, additional marking must be present such as dot or bevel (or just text).

 

and if the parts are packaged in tape reel, it is common that pin1 is on side nearest the perforated tape edge.

 

The datasheet appears to show a dot near pin 1 (a slightly recessed hole usually) and a bevel is common on surface mount packages.

I was just thinking.... I don't think I've ever seen a DIL (Dual In Line) package where the text is not right-side-up when pin 1 is at the lower left. Has anyone observed otherwise?

 

Please, somebody attach the datasheet for the part the OP's asking about. Please

 

Please, somebody attach the datasheet for the part the OP's asking about. Please

The datasheet is in the link posted in the original post.
The graphics in post #3 by panic shows the various ways to identify chip orientation.

 

How can I know the pin order in this chip?

Datasheet shows a dot at pin 1. One side has all 4 pins (drain) and the other side 3 pins (source) connected together which makes it simple to find pin order even without any markings.

 

Rather than make random guesses based on what we see on other devices, note on the data sheet that pins 5 thru 8 are all DRAIN pins tied to each other. I am thinking that should be possible to verify with an OHM METER.
ALSO NOTE that pins #1, #2, and #3 are the three source pins, apparently tied together. Pin #4 being the Gate pin, should have a higher resistance to the other pins. So with a simple OHM METER check it should be possible to verify which side is the four drain connections. ALSO, note that pins #4 and #5 are the ones spaced farther from the others, IF the data sheet is correct.
IN fact, the data sheet does display a top view with both pin numbers and pin designations given.