# Simulating a XR2240

Discussion in 'General Electronics Chat' started by shoptodip, May 3, 2012.

1. ### shoptodip Thread Starter New Member

May 6, 2011
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I would like to simulate a ckt which contains XR2240 Ic .But I am not finding them in N.I multisim or protius simulator software can any one help me?

2. ### Wendy Moderator

Mar 24, 2008
20,735
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I have move this to a more appropriate forum, where it is likely to get more help. Good luck, and welcome to AAC!

I have also removed your other posts from other peoples threads. A thread belongs to the OP (original poster). Trying to take over someone elses thread is called hijacking, which is not allowed at All About Circuits. You have a thread of your very own, it belongs to you.

Last edited: May 3, 2012
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3. ### shoptodip Thread Starter New Member

May 6, 2011
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thanx mod. Hopping for help from genius peoples.

4. ### crutschow Expert

Mar 14, 2008
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It is perhaps unlikely that you can find a simulation model for the XR2240. Models for complex chips are hard to come by.

You may have to make your own model using discrete logic gate models. Since the device is fairly simple, consisting of a programmable counter, a flip-flop, and an oscillator, it shouldn't be too hard to make a functional model.

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5. ### shoptodip Thread Starter New Member

May 6, 2011
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Can any one help me by giving the inner circuit of XR2240

6. ### Papabravo Expert

Feb 24, 2006
10,021
1,757
Your best bet is to understand the Voltage Controlled Oscillator (VCO). The sine function can also be obtained with a dual op-amp integrator that solves the differential equation of a simple harmonic oscillator(aka a Quadrature Oscillator). There are simple relaxation oscillators that will produce a square wave. If you integrate a square wave you will derive a triangle wave.

http://en.wikipedia.org/wiki/Voltage-controlled_oscillator
http://en.wikipedia.org/wiki/Relaxation_oscillator
http://www.ti.com/sc/docs/apps/msp/journal/aug2000/aug_07.pdf
http://en.wikipedia.org/wiki/Multivibrator

Those references should keep you off the streets for a while.

7. ### Papabravo Expert

Feb 24, 2006
10,021
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Probably not. The chip was obsolete before simulators were widely available. Since the chip is no longer being manufactured there is little point in anybody expending any effort on making a model.

8. ### crutschow Expert

Mar 14, 2008
12,522
3,064
It you look at this data sheet, you will see a block diagram for the internal functions. Just use suitable available circuit models to simulate those blocks e.g. binary counter, time base (clock or oscillator) and flip-flop.

9. ### crutschow Expert

Mar 14, 2008
12,522
3,064
Papabravo, you are confusing the poor OP. The XR2240 is a Programmable Timer/Counter. I believe you are referring to the Function Generator chip which has a similar part number.

10. ### Papabravo Expert

Feb 24, 2006
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You're right. The function generator was the XR2206. Sorry about that. Exar, the company that originally made those chips, is sorta like Gen. Franco -- still dead.

11. ### SgtWookie Expert

Jul 17, 2007
22,182
1,728
Rumors of Exars' demise have been greatly exaggerated:
http://www.exar.com/

But, demand for analog function generator ICs has dropped to a dribble ... unfortunately, manufacturers cannot justify keeping such ICs alive for hobbyists alone, as they don't drive the market.

12. ### Papabravo Expert

Feb 24, 2006
10,021
1,757
The name lives, but I question weather it is the same company after mergers, acquisitions and divestments in the 1994-1995 time frame.

13. ### shoptodip Thread Starter New Member

May 6, 2011
5
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for simulation can I use any other Ic which replace XR2240. Thanx all that you are helping me.