TLV1805-Q1: NO POLARITY INDICATOR FOR PIN 1

dave miga

Part Number: TLV1805-Q1

The chip has no markings indicating pin 1, looks entirely different from the spec sheet. Marked only 1ULF with no other polarity indicator. WHICH IS PIN 1??

10 months ago

0 Paul Grohe 10 months ago

TI__Guru 53946 points

Hello Dave,

The direction of the text determines pin 1.

Reading the text normally left to right, pin 1 would be the lower left pin.

So:

6 5 4

1ULF

1 2 3

Pin1
bottom left

Some packages may have a slight bevel running down the pin 1 edge of the package. There should be a dot or line along the left edge...may be difficult to see with laser marked devices (need to get the light angle just right...)

0 Clemens Ladisch 10 months ago

Guru 284830 points

There should be a stripe at the left side. (And lines at the top/bottom as a binary date code.)

0 dave miga 10 months ago in reply to Clemens Ladisch

Prodigy 60 points

Thanks for the info. The stripe on my units cannot be seen I suppose because of improper laser markings that are too light to see. Perhaps TI should investigate this problem and solve it by simply using a thicker or deeper laser.

0 Clemens Ladisch 10 months ago in reply to dave miga

Guru 284830 points

I would expect all markings to be done by the same laser. Can you show a photograph?

0 dave miga 10 months ago in reply to Clemens Ladisch

Prodigy 60 points

I made about 12 shots using my Dino-Lite digital microscope with every light source I could find, direct, different angles, etc. the markings are so faint that I needed Photoshop to enhance them enough to see. The attached photo was the best I could manage and as you can see, the expected line showing the pin 1 area is too short besides being too thin and too light so it doesn't appear to be a line, just another letter next to the part number. In the past these lines were always thicker and obvious, spread across the entire top (side?) of the chip.

Hmmm...seems that there is no option in this forum script for a jpg upload. Contact me directly and I can send it via email.

0 Clemens Ladisch 10 months ago in reply to dave miga

Guru 284830 points

To insert an image, click "Insert" / "Image" in the menu below the editor box.

0 dave miga 10 months ago in reply to Clemens Ladisch

Prodigy 60 points

File upload button only allows URL, no browse button for a jpg on my computer..

0 Clemens Ladisch 10 months ago in reply to dave miga

Guru 284830 points

The grey "Upload" label actually is a button.

0 Paul Grohe 10 months ago in reply to dave miga

TI__Guru 53946 points

Hi Dave,

Click the "Insert" pull-down below, then select "Image/Video/File".

This is not intuitive... but click on the grey "Upload" text under the box, and a file browser should pop up.

Or you can just paste a screenshot directly into the editor, as I did above.

0 Paul Grohe 10 months ago in reply to dave miga

TI__Guru 53946 points

Hi Dave,

And also a picture of the box and/or reel labels.

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TLV1805-Q1: NO POLARITY INDICATOR FOR PIN 1