555 Timer IC Working of Astable,Mono-Stable,Bi-Stable Modes and Specifications

555 Timer IC Working

In this article explains 555 Timer IC Working of Astable, Mono-Stable, Bi-Stable Modes and Specifications on www.circuits99.com.

The 555 timer IC is a very cheap, popular and useful precision timing device. The 555 timer IC is an integral part of electronics projects. 555 timer IC it is a simple project involving a single 8-bit micro-controller and some peripherals or a complex one involving system on chips, 555 timer working is involved. These provide time delays, as an oscillator and as a flip-flop element among other applications.


555 timer IC

555 timer IC

The 555 Timer IC generally operates in 3 modes. A-stable, Mono-stable and Bi-stable modes.

1. Astable mode

Astable Mode there will be no stable level at the output. So the output will be swinging between high and low. This character of unstable output is used as clock or square wave output for many applications of 555 IC timer.

2. Mono-stable mode

This Mono-Stable Mode consists of one stable and one unstable state. The stable state can be chosen either high or low by the user. If the stable output is set at high(1), the output of the timer is high(1). At the application of an interrupt, the timer output turns low(0). Since the low state is unstable it goes to high(1) automatically after the interrupt passes. Similar is the case for a low stable monostable mode.

3. Bi-stable mode

In this Bi-Stable Mode, both the output states are stable. At each interrupt, the output changes from low(0) to high(1) and vice versa, and stays there. For example, if we have a high(1) output, it will go low(0) once it receives an interrupt and stays low(0) till the next interrupt changes the status.


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