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."
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.
TI Comparators (CMPS) Applications Group
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