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I bought a DS3232MZ+, and I noticed that in the datasheet, the pins schematic looks like this:

datasheet view

However, when I received my chip, I noticed that in reality it looks like this:

reality

Usually I tell which side is which by the name positioning, but as you can see the name is rotated so I'm confused. Moreover, in the the datasheet there can be found a "typical circuit" which looks like this:

typical circuit datasheet

which is even more confusing, as it differs from the pin order schematic, where two pins have switched sides.

I'm a newbie in electronics, can anyone help me understand this schematic and help me figure out which pin is which for my second picture?

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1 Answer 1

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Usually I tell which side is which by the name positioning

Totally wrong. You tell which is the first pin by looking at the dot on the IC package. Look at the package from the top, with that dot / marking on the left and pin 1 is the one from the lower left. Starting from here, pins are numbered counter clockwise.

enter image description here

enter image description here

it differs from the pin order schematic, where two pins have switched sides

A schematic is just a schematic, it has nothing to do with the real pin order. Usually, pins with related functions are grouped together to draw a good looking and easy to understand schematic.

Also think about this: you have a 0.25 W and a 10 W resistor. Both have the same schematic symbol. On the real PCB, the first has a 10 mm footprint, and the other has 22-27 mm footprint.

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  • \$\begingroup\$ Thank you, I never noticed those. Upon looking closer I noticed there is an extremely tiny "+" in one corner. \$\endgroup\$ May 15, 2014 at 7:17
  • \$\begingroup\$ @AlexandruSeverin there should be. These are standards. If you can't see the "+" then look for the notch. \$\endgroup\$
    – Cornelius
    May 15, 2014 at 7:19
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    \$\begingroup\$ Or the dimple, or the the triangle/non-squared corner. \$\endgroup\$
    – Passerby
    May 15, 2014 at 16:36
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    \$\begingroup\$ Or, on many surface mount packages, a bevelled edge indicates the pin 1 edge. \$\endgroup\$ May 17, 2014 at 16:53

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