What is a 555 timer?

1.The nature of the 555 timer

The 555 timer is also called integrated time base circuit or integrated timer. It is a digital, analog hybrid medium scale integrated circuit, which can produce time delay and multiple pulse signals. It is widely used.

555 timer has two types: bipolar type and CMOS type. The structure and working principle of the two types are similar. The last three digit numbers of almost all types of bipolar products are 555 or 556; all the final four digit numbers of CMOS products are 7555 or 7556, both of which have the same logical function and pin arrangement, and are easily interchangeable.

555 and 7555 are single timer. 556 and 7556 are dual timers. Bipolar power supply voltage Vcc = 5 ~ 15V, the maximum output current can reach 200 mA, CMOS power supply voltage is 3 ~ 18V.

2.555 Timer application control voltage pin ( 5 feet ) no more than the signal, usually by decoupling capacitor to ground pin, decoupling capacitor can remove the sharp pulse interference, to improve the anti-jamming capability, the decoupling capacitor often selects the non-polar capacitor of 0.01F, and the capacitance can be changed according to the disturbance. If there is no interference, the terminal can also be suspended directly.

The 555 timer is mainly composed of an external resistor and a capacitor to form a charging and discharging circuit, and two comparators are used to detect the voltage on the capacitor, to determine the level of the output level and the on-off of the discharge switch.

In this way, the pulse waveforms such as delay circuit, multivibrator, monostable trigger, Schmitt trigger, from microseconds to tens of minutes, can be conveniently formed and shaping circuits.

If you want to know more, our website has product specifications for the timers, you can go to ALLICDATA ELECTRONICS LIMITED to get more information.