1
\$\begingroup\$

I have an OPA4353 IC, that i want to figure out the pinout from the schematic. I know this is basic stuff, but since this is the first time I am doing this, and I will be designing a PCB from it, that takes time to arrive and money, I want to make sure I make this right.

This is the image from the datasheet:

pinout image from datasheet

And this is the actual IC:

photo of IC

I have labeled what I think is the pinout on the IC, with green numbers.

Is my assumption correct?

I came to this conclusion because the datasheet picture has a circle next to the pin named "1". I think the actual IC has that circle on the bottom left, therefore I arrived to the conclusion that the pin 1 must be there.

Is my assumption correct? What about pins 9-16? Are they in the correct order?

\$\endgroup\$
3
  • 1
    \$\begingroup\$ Default view is top down. CCW direction for pin # increments . pin 1 is an index sometimes shown by a different pad design or a dot to assist in manual assembly to align with dot on IC. also called fiducial marks. \$\endgroup\$ Oct 28, 2020 at 0:39
  • \$\begingroup\$ user1584421 - Hi, You said: "the actual IC has that circle on the bottom left, therefore I arrived to the conclusion that the pin 1 must be there" As long as there is only 1 indentation on the top surface (and that is typical on the SSOP, SOIC etc. case styles) then yes, that is the pin 1 marker. However, note that some QFP / LQFP packages, for example, can have multiple indentations in the top, making it less obvious which is the pin 1 marker. I will try to add some links to previous questions on this topic, for future reading and so they appear in the "linked" column on the right. \$\endgroup\$
    – SamGibson
    Oct 28, 2020 at 0:55
  • \$\begingroup\$ Some relevant previous questions, for different IC packages: "SN75176 pin 1, no semicircle", "How do I identify Pin 1 on a chip with no corner mark", "Which of these marks signifies Pin 1 on the STM32F (LQFP64)?". \$\endgroup\$
    – SamGibson
    Oct 28, 2020 at 1:06

1 Answer 1

3
\$\begingroup\$

I have labeled what I think is the pinout on the IC, with green numbers.

Is my assumption correct?

Yes!

Is my assumption correct? What about pins 9-16? Are they in the correct order?

Yes!

Your numbering shown in green is correct, for all the reasons you stated.

Here is your photo of the IC with green numbering, rotated clockwise by 90° so the circular "dot" (indentation) is top left, to match the image in the datasheet.

Original photo of IC rotated clockwise by 90 degrees

Now you can clearly see that your green numbers match the pinout numbering from the datasheet.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.