NE555 IC that has an 8-pin (leg) is one of the electronic components is quite well known, simple, and versatile with size less than 1/2 cm3 (cubic centimeter). Basically, the main application is used as the IC NE555 timer (Timer) with monostable circuit operation and Pulse Generator (pulse generator) with astable circuit operation. In addition, it can also be used as a Time Delay Timing Generator and Sequential.
Judging from the manufacturer, IC NE555 is a manufacturer of Philips and Texas Instruments. Actually many companies that make IC similar to this NE555. Each company issued with the design and the technology is different. For example, National Semiconductor makes and call it by the name of LM555, Motorola / ON-Semi designing with CMOS transistors so komsusi powernya small enough and named MC1455.
Maxim makes its CMOS version under the name M7555. Although the name is different, but mutually compatible and the diagram functions (functions and the pin position) from each other. Although compatible with each other, there are still several different specific characteristics such as power consumption, maximum frequency and so forth. All of them, at present more details on each manufacturer’s datasheet.
Practically, the function and application of IC NE555 is widely used among others as a regulator of the alarm, as the driving DC motors, can be combined with IC TTL (transistor-transistor logic) and as input a digital clock for the “purposes of the desired” (if only for a digital clock usual , many IC that can be directly used), can also be used in a series of touch switch, and when combined with infrared or ultrasonic, NE555 can be used as a transmitter or remote control.
Especially when combined with modulation techniques and some electronic components that support, can be produced remote control multi channel that can control some other electronic device in a remote (indeed reach the distance is not too far away, at about 10m – 20m. The difference with the use of radio frequencies) , For practical purposes in making a circuit with this IC, you need to know is the position and function of each leg only, which can be seen as follows:
As for knowing how to work and the physical structure of the IC NE555 detail can be seen from the circuit / internal components.
In the block diagram above, the internal IC NE555 tiny consists of: two comparators (comparator voltage), 3 pieces of resistors as the divisor tengangan, 2 pieces of transistors (in practice and analysis work, transistors are connected to the pin 4 is usually directly connected to the Vcc), 1 piece SR flip-flop that will set the output on a particular logic state, and 1 inverter
By looking at Figure 2 and Table 1, in general the internal workings of this IC can be explained that, when the pin 4 as a reset by a voltage of 0V or logic low (0), then the output on pin 3 bound to logic low as well. Only when pin 4 (reset) by signal or logic high (1), then the output of this NE555 will change according to the threshold voltage (pin 6) and a trigger voltage (pin 2) are given.
When the threshold voltage on pin 6 exceeds 2/3 of the supply voltage (Vcc) and logic outputs on 3 pin logic high (1), the internal transistor (Tr) will turn-on so that it will lower the threshold voltage to less than 1/3 of the supply voltage. During this time interval, the output at pin 3 to logic low (0). After that, when the input signal or trigger in the pin 2 which logic low (0) begin to change and reach 1/3 of Vcc, the internal transistor (Tr) will turn-off.
Switching transistor turn-off will increase so that the output voltage IC NE555 threshod is originally a logic low (0) will return a logic high (1). Actually, the workings of the base IC NE555 is a full combination and not in spite of all the internal components consisting of three resistors, 2 comparators, 2 transistors, 1 flip-flop and 1 inverter, all of which will be discussed on another occasion , Simultaneously with the circuit / external components that support them.