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555 timer astable monostable

555 Timer PRO provides an array of design wizards, circuit blocks and information panels that facilitate the use of the 555 timer. Component value calculations for the 555 take into account the supply voltage, timer fabrication (CMOS or Bipolar), and, where appropriate, load currents.

Features include:

  • 555 timer synopsis - includes pin functions, fabrication differences, component selection
  • 22 timer design wizards - 14 for the astable mode, 8 for the monostable mode
  • input circuitry - for gating an astable or triggering a monostable. Input categories are switch, touchplate, continuity, liquid level, AC detect, light, sound, and temperature.
  • counter wizards - facilitate divide by/count to strategies using common binary and decade counters
  • output circuitry - that can be activated by the 555 timer. Includes switching loads, driving motors, driving LEDs, lamps, numeric and bargraph displays, and audio, ultrasound and RF outputs
  • general - voltage reference design, "best pair" resistor substitution, logic families reference, IC pinouts for all ICs used in 555 Etcetera
  • PDF file output - write all project circuit blocks to convenient PDF file

555 Timer PRO and 555 Timer Lite (freeware) are combined in the same application.

Click on any image to enlarge...

Main screen with Lite/PRO option

555 Timer PRO main screen
One of the 555 timer overview screens

555 Timer PRO overview screen
Astable mode calculator

555 Timer PRO astable screen
Circuit application example

555 Timer PRO example screen

Comparison of 555 Timer Lite, 555 Timer PRO and 555 Etcetera:


555 timer design software Lite PRO Etc
Timer design wizards
Astable mode, duty cycle > 50% 1 4 4
Astable mode, 0%-duty cycle-100% 1 9 9
Astable mode, squarewave 0 3 3
Monostable mode (one-shot) 1 8 8
Adjusted for supply voltage, fabrication, load currents   YES YES
Support ciruitry
Input circuit library 4 47 47
567 tone decoder wizard   YES YES
Photodiode amplifier wizard     YES
Digital counter/divider wizards   YES YES
Output circuit library 5 41 41
Triac snubber wizard   YES YES
LM386 audio amplifier wizard   YES YES
Voltage reference wizards   YES YES
Best-pair resistor wizard   YES YES
Logic family overview   YES YES
Active filter design wizard, LP, HP, BP, BS to order 6     YES
Operational amplifier design wizards     YES
Transistor amplifier design wizard     YES
Download for evaluation YES YES  
Price (USD) Free $19.95 $29.95

555 Timer PRO and Lite download

555 Timer PRO and 555 Timer Lite are combined in one application. The Lite mode offers astable and monostable calculators as well as other useful 555 timer information, and can be used indefinitely. Purchase of a licence and registration of the product enables the full 555 Timer PRO mode,

A single-user license authorizes the licencee (only) to operate the software on two computers, such as a work computer and a home computer.

This application or its setup file, or any portion thereof, may not be redistributed by any means whatsoever, except with the expressed permission of Schematica Software.


Compatible with Windows 98,NT,ME,2K,XP,Vista


EXE setup file:

555_Timer_PRO_Setup.exe 3.91 MB 555 Timer PRO

Archived setup file:

555_Timer_PRO_Setup.zip 3.60 MB 555 Timer PRO


Please report any dowloading problems to support@schematica.com.