The SE555 is military grade IC and has operating temperature range of -55 to +125 degree Celsius. The NE555 is a civilian grade IC and has operating temperature range of 0 to +70 degree Celsius. There are two versions of the IC available namely military and civilian grade 555 timer. How IC 555 WorksĪ standard IC555 consist of 25 transistors, 15 resistors and 2 diodes integrated on a silicon die. However, some hypothesis claims that the selection of the name has no relation to the internal components of the IC, it was arbitrarily selected. If we look at the internal block diagram of IC 555 we find three 5K ohm resistors connected in series for deciding the timing factor, so probably that's how the device got its name IC 555 timer. The Signetics Company is owned by Philips Semiconductor. That’s one IC 555 for every 7 people in the world.

It is estimated that about 1 billion IC 555s are manufactured every year. IC 555 was introduced in 1971 by a company called “Signetics” it was designed by Hans R. In this article we are going to look back at history of IC555, their 3 operating modes and some of their specifications. It would be one of our first IC to use in electronics. You can see the lm555 chip pinout diagram image below.Our hobby world would be less interesting without IC 555. The trigger pin is pin 8, and when the voltage at the pin falls below half of the control voltage, the interval starts and the output reaches a high state. Furthermore, its dual comparators and flip-flop enable it to operate in Astable, Monostable and Bistable mode. It also has three resistors of 5K value hence the name 555. Meaning it has eight different pins with different functions for the IC. The following are the key application areas for the chip: It has limited built-in ESD protection.It has an operating temperature of 70 degrees celsius.The Source current of the output is 200mA.The minimum recommended electrolytic capacitor is 1-μF.The minimum recommended capacitor value is 0.1μF.Its trigger voltage is 1.67 in parallel with +5V.It requires a voltage supply within 4.5v to 16v.According to its datasheet, some of the main specs of the chip are:

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