Project Report - D EVICE MODELL I NG SPICE NETLIST - IC 555...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
DEVICE MODELLING SPICE NETLIST - IC 555 IN ASTABLE MODE SUBMITTED BY: VISHAKH LAKSHMINARAYAN BT07ECE059 (N4) INTRODUCTION
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
IC 555 is a timer IC. It is the most versatile of the timers that are present. IC 555 can be used in two modes: 1. Monstable mode 2. Astable multivibrator ASTABLE MULTIVIBRATOR: An astable multivibrator, often called a free running multivibrator, is a rectangular-wave-generating circuit. Unlike the monostable multivibrator, this circuit does not require an external trigger to change the state of the output, hence the name free running. The time during which the output is either high or low is determined by two resistors and a capacitor, which are externally connected to the 555 timer.
Background image of page 2
OPERATION: Initially when the output is high, capacitor C starts charging towards Vcc through Ra and Rb. However, as soon as the voltage across the capacitor equals 2/3 Vcc, comparator 1 triggers the flip-flop and the output switches low. Now capacitor starts discharging through Rb and transistor Q1. When the voltage across C equals 1/3 Vcc, the comparator 2’s
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/15/2010 for the course ECE 1234 taught by Professor G.wdwdw during the Spring '10 term at St. Johns Seminary.

Page1 / 13

Project Report - D EVICE MODELL I NG SPICE NETLIST - IC 555...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online