A newbe question

[whomeno]

which end is pin 1 on a cd4013be, 1 end has a u cut out and the other end has a dot?

[Marcos - Munky]

Cut or dot is the side with the 1st and last pins of an IC.  1st pin is the one on the left and the last pin is the one on the right, looking to the IC with the cut or dot pointing up.

[whomeno]

yes but which end is pin 1 on the cut side or the dot side it has both on chip

[marcelomd]

Cut side is pin 1. If there is a cut AND a dot, the dot probably is the injection mould mark.

Or you could post a picture =)

EDIT: My intuition is that only the cut is deliberate. See picture. Lots of dots, but only one cut.


EDIT 2: This is just an observation, not a rule, but if you put the text in the right orientation, pin 1 is on the lower left.

[whomeno]

here is a pic
https://www.mouser.com/ProductDetail/Texas-Instruments/CD4013BE?qs=pt%2FIv5r0EPc2Chv9B9JKAA%3D%3D

[marcelomd]

here is a pic
https://www.mouser.com/ProductDetail/Texas-Instruments/CD4013BE?qs=pt%2FIv5r0EPc2Chv9B9JKAA%3D%3D

Datasheet says pin 1 is on the notch side. Page 27 =)

[whomeno]

ok thank you

[PRR]

Any orientation dot is on the corner.

I do not see one in that stock photo. The U-notch is clear.

Oversize stock image: https://www.mouser.com/images/texasinstruments/hd/ITP_TI_PDIP-14_N_t.jpg

Circles in the middle vent air out of the mold and are not for orientation. (Usually there are two, or none, or one on the bottom-- I guess this molder is OK with one, or the U-notch is also a vent; sometimes it is a mystery.)

Good overview: https://www.evilmadscientist.com/2010/basics-finding-pin-1/

[marcelomd]

And now here is a chip that has less of a "direct" indication of its orientations– no dot or half-moon shape. As we discussed earlier, you can rely on the orientation of the text in cases like this, and imagine an effective polarity mark on the left hand side of the chip. Pin 1 is on the lower left hand side.

Hah! I KNEW it!