It generally goes clockwise from the marker when the pins are viewed from the bottom of the part, CCW when viewed from the top. If you know the part #, you can probably find a datasheet on the web that would clear up your doubts.
-- john
I have a DIP chip that has a notch on one side and a big dot on another (opposite) side. I am a little bit confused as to where pin 1 is. I think that it's to the left of the notch, if I hold the notch upwards, but I am not sure. Why s there a dot if there is also a notch?
i
bottom view, pin 1 is clock wise to the notch most likely.
-- Real Programmers Do things like this. http://webpages.charter.net/jamie_5
Manufacturer and part number?
Regards,
Boris Mohar
Got Knock? - see: Viatrack Printed Circuit Designs (among other things)
void _-void-_ in the obvious place
Look in the data sheet- this will tell you.
I can't imagine what you mean. Scan it and post in abse perhaps ?
In the meantime get the data sheet ! What is the part btw ?
Graham
That's a really obtuse answer ! Who looks at the bottom view ? Will the markings be visible from the bottom ?
Graham
It has been a standard since the 1930s.
Octal valve pins were counted clockwise from the spigot, later all-glass vales were counded clockwise from a pip or a missing pin. It made sense if you were looking at the valveholders on the underside of a chassis.
When ICs were introduced, exactly the same system was use - but some manufacturers began to confuse the issue by printing the diagrams as anti-clockwise viewed from above. It still made sense from the underside of a printed circuit board, the designer and serviceman just had to remember that the data book was printed backwards.
On a lot of IC packages, the pisition of Pin 1 *was* marked so it could be seen from the bottom (e.g. a notch in one end of the package, from which you count clockwise).
Sounds as though they are still keeping to the standard.
-- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
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