How to determine the pin order of an IC chip

The method of identifying the digital IC pins is to point the letters and codes on the front of the IC to yourself, so that the positioning mark is facing the lower left, then the pin in the bottom left is the first pin, and then count the pins in the counterclockwise direction, which is the second pin, the third pin, and so on.

Integrated circuits usually come in several packaging forms, such as flat, double-in-line, and single-in-line. Regardless of the type of integrated circuit, the housing has a mark on the shell for identifying the pins to be sorted and positioned (or called the first pin). For flat packages, a small dot (or small circle, color dot) is usually marked on one end of the front of the device.

The positioning marks for molded double in-line integrated circuits are usually arc notches, circular dimples, or small circles. There are more marking patterns of imported ICs, such as colored lines, black dots, square color rings, two-color rings, and so on. Figure 1(a) and (b) illustrate the pin location markings that are common for digital integrated circuits in both low-profile and dual in-line plastic packages.

Figure 1(c) is a dual-in-line digital integrated circuit in a ceramic package, which is marked with a metal sheet and a color dot.

Figure 2(a) and (b) show the positioning marks and pin sequencing of analog ICs, which are similar to those of digital ICs. There are a few special pins in the analog IC, as shown in Figure 2(c) and (D).

Figure 3 and Figure 4 show the pin sorting of various single-column in-line ICs. When counting pins, put the pins of the IC downward, then the positioning mark is on the left side (the same as the double column in-line), and count from left to right to get the pins sequence number.

Some imported IC circuits have reverse pin ordering. These ICs are followed by the suffix "R". The ones without "R" at the back of the model number are the forward pins, and the ones with "R" are the reverse pins, as shown in Figure 5. Attention should be paid to the number of pins to identify such ICs.

The internal structure of the dual-base diode and the pin measurement method.

Draw a square pattern, and mark "East, South, West, North" in clockwise direction on the four sides, and the drive is set.

If there is an obvious dot or other mark on the face end of the integrated circuit as the first foot, this column is arranged in order, and the other column is arranged in the opposite side of the front and the end as the starting foot.

No.23 03 Electronics: CD4026 Counter Chip Pin Definition and Decoding Driver Function.

These are the most basic, when you learn the CPU power supply chip to explain to me, I will give you extra points, the CPU power supply chip has many pins that do not know the meaning.

1. The chip with a horizontal bar is used to identify the direction.

For some double-row in-line or double-row patches, there is a horizontal line on the surface of the chip leak, which is the direction identification point of the chip pin. The chip is placed flat, the first pin is on the left side of the horizontal bar, the last pin is on the right side, and the pin number is increased in the counterclockwise direction.

This dot identification method is very common for double in-line chips. This dot is the direction identification point. The marking method is similar to that of the marking method with horizontal bars.

Dust the chip flat with the first pin to the left of the dot and the last pin to the right of the dot. The pins are numbered in a counterclockwise direction.

3. Identification direction of chips with gaps.

It is most common to use a semi-circular notch as a point of direction identification. To the left of the notch is the first pin, and to the right of the notch is the last pin, in counterclockwise increments.

4. Chip identification direction without identification points.

There are also many chips, the surface of which has neither dots, horizontal bars, nor gaps, only letter silk printing. For this kind of chip, put the chip forward so that the direction of the silk screen is in the positive direction, then the left pin is the first Zen pure rotten one, the right side is the last pin, and the number increment direction is also counterclockwise.

5. Identification direction of the chip with dots.

LQFP quad flat package chips are more common, and these chips are identified by dots. To the left of the dot is the first pin, and the pin on the other side is the last pin. The increment direction is counterclockwise.