How are chip pins numbered?

By convention, the pins on an IC are numbered counterclockwise, starting with the upper-left pin closest to the clocking mark. So, for example, with the clocking notch orienting the chip at the 12 o’clock position, the pins of a 14-pin IC are numbered 1 through 7 down the left side and 8 through 14 up the right side.

How do I read my IC chip number?

All IC chips have a two-part serial number. The first part of the serial number delineates the manufacturer’s information. The second part of the serial number indicates the IC’s technical specifications. Many IC manufacturers produce identical chips with the same technical specifications.

How do I find my pin 1?

Pin 1 is on the lower left hand side. If you look very closely, you’ll see that there is one additional polarity marking feature, in that this chip also has a very slightly beveled front edge.

What indicates the orientation of a logic chip?

The “orientation” of the part (which way you look at it to determine pin 1) is usually indicated by a notch on the end that has the lowest- and highest-numbered pins; on some parts there is instead a dot or marking on the surface of the package adjacent to pin 1.

How many pins does IC have?

The pins are numbered anti-clockwise around the IC (chip) starting near the notch or dot. The diagrams show the numbering for 8-pin and 14-pin ICs, but the principle is the same for all sizes.

What two methods are used to indicate pin number one on an IC?

Polarity Marking and Pin Numbering This means the package has to have some way to convey which pin is which. Most ICs will use either a notch or a dot to indicate which pin is the first pin. (Sometimes both, sometimes one or the other.)

What marking on a ribbon cable identifies Pin 1?

The red stripe on ribbon cables is used to indicate that this is pin 1 of the cable. If the ribbon cable is plugged in backwards, the two devices will not be able to communicate properly.