OPA2171: Pinouts for SOT-8 "D" package for OPA2171

Part Number: OPA2171

Just to clarify, there is no indication on the OPA2171 datasheet (or Google Images) for that matter that tells where Pin 1 is.

This is an SOT-8 "D" Package surface mount component.

There is no dot on the physical chip, only a Line which I assumed indicated Pin 1, but I am no longer in the business of assuming anything, we even called TI and couldnt get a straight answer to such a basic question.

so here is a link I found that confirms.


"There’s a printed bar on the left hand side of this chip to act as a polarity indicator, taking the place of the half-moon shape."

1 Reply

  • Hi Alex,

    Yes. The stripe at the top is the Pin 1 marking.

    The convention for most plastic rectangular packages is:

    looking at the package in a horizontal direction (pins facing up and down), reading the text correctly from left to right, pin 1 is in the lower left. The pins are numbered counter-clockwise across the bottom and around to the top (so bottom is 1-8 left to right, and top row is 9-16 right to left).

    Also notice that there is a bevel in the package along the length of the pin 1 edge. This is also common on SOT-23 packages.

    So there are several clues as to the pin one position:

    1. Dot or bump next to pin 1
    2. Notch, bar or stripe at the pin-1 end of the package
    3. Bevel along the pin 1 edge of the package
    3. The text orientation
    4. Notch in "foot" or a wider pin 1 (rare)
    5. Beveled pin-1 corner (rare)
    6. Angled edge on any thermal pad under the package

    Dots and bars are preferred because of optical inspection and placement.


    Paul Grohe

    TI Comparators (CMPS) Applications Group