 
|
 |
|
 |
| What is Electromagnetic Education? |
|
|
|
|
|
EACH integrated circuit (IC) has a specialized function. The 4011BCN shown above is known as a Quad 2-Input NAND Gate IC. It incorporates NPN and PNP transistors and diodes in order to perform logical calculations. The markings on the IC help in locating the 'datasheet' with more information on what functions a particular chip performs. Chip search engines can help locate these resources.*
THE top mark order code on the first line of the IC (FP0230SD) can be deciphered by codes from the manufacturer. For instance, the 'F' is the Fairchild Semiconductor logo. 'P' is the Assembly Plant, in this case Penang, Malaysia. '0230' is the date code, indicating when IC was manufactured, which it is estimated may be the 30th week of 2002. 'SD' is the site of Fabrication code. |
|
| THIS specific IC is a dual-in-line package (DIP) with metal pins that extend from the molded plastic case, to extend through a circuit board for soldering. This specific IC has 14 pins, which the datasheet provides the numbering for. |
|
|
ELECTRICAL current passes through each pin on the chip and performs functions along the way. For example, Pin #14 connects positive electrical voltage to the IC, and Pin #7 connects negative electrical voltage.
SYMBOLs become necessary in order to 'see through' this specific chip to its internal functioning hidden inside its standardized packaging. A datasheet helps to visualize its 'logic' gates, with letters A B C D inside the symbols for the four NAND gates on the chip. |
|
|
PINs on the chip, then, send electrical current through their logical structure and perform logical functions. One example would be if Pin #1 and Pin #2 were each sending input signals into NAND gate C, which would then be output at Pin #3 as either a high or low signal (or zero or one). Though what does this symbol for actually NAND represent? What logical function does it perform?
NAND logic gates are an inversion of AND logic gates, sending a low output signal only when all input signals are high. A 'truth table' demonstrates this: |
| Pin #1 | + | Pin #2 | = | Pin #3 |
| 1 (input) | + | 1 (input) | = | 0 (output) |
| 1 (input) | + | 0 (input) | = | 1 (output) |
| 0 (input) | + | 1 (input) | = | 1 (output) |
| 0 (input) | + | 0 (input) | = | 1 (output) |
| IN other words, this integrated circuit will only output 'FALSE' signals (or low, or zero) from its NAND logic gates when both inputs sent (to the associated field effect transistor switching) are 'TRUE' (or high, or one) at any of the four gates of the IC. |
|
|
LOOKING at Pins connected to four NAND gates of the IC in the above image, the Truth Table can be seen in relation to how electrical current is sent through a logic circuit which then outputs various signals, in turn. For instance, in GATE A the pins input signals (1,1) and return an output through a third pin (0). So too in Gates B (1,0) outputs 1, Gate C (0,1) outputs 1, as does Gate D (0,0) with a NAND output of 1.
ICs enable complex functioning, in this case how a NAND logic gate works in an electronic circuit. Such a chip can be designed into a circuit to build upon this functionality, for more complex results. There are also thousands of such chips with special functioning which can be either analog or digital-- they can look identical in packaging yet have entirely different attributes. It is for this reason that a complex understanding of ICs and electronics components is worth investigating further, as it is where 'hardware,' 'software,' and 'thinking' often associated with today's developments can be found in one place, in the details of these otherwise commonplace yet invisible devices. LEARNING more about just one chip, logic, transistors, semiconductors, circuits, electrical current, calculation, and other topics can be understood in an interrelated context. Electronics kits can help one better understand the basic nature of these devices, though designing custom circuits requires more knowledge. Today, microcontrollers are also a fascinating area to explore dynamic relationships in electromagnetic knowledge. (bc 1.20.2004) |
-= What is Electromagnetic Education? =-
<-the-Electromagnetic-Internetwork->