Need help designing a digital circuit

[IndiJones]

tca965 аналог

I need to design a digital circuit that will output logic 1 and lit an LED when the input analog voltage is within a certain range (say 2-5 volt) and will output logic 0 elsewhere. A schematic would be very helpful. Thanks in advance!

 

[Alexg]

What you need is called a "window comparator". Follows a link to one of many many ways of doing it. Do a search with windows comparator and you will find a lot of different circuits to opt from.

**broken link removed**

Best regards,
Alexg

 

[sigint]

Use a window comparator for indication only, not for voltage control - whwn used for control it will always oscillate.

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[MITSUKO]

I think the chip you need is
TCA965 , by siemens if i'm not mistaking .
You can set the lower and higher trippoint and it gives you a signal inside window or without to high or without to low .
I must have a data sheet here somewhere , i'll see if i can find it .

Mitsuko

 

[sigint]

LM324

 

[IndiJones]

Thanks! Any schematic would be very helpful.

 

[sigint]

Check out Poptronix magazine they recently, within the last couple of years, had a column that addressed comparator usage. If that doesn't prove fruitful I think I have a couple of old designs I could share.

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[IndiJones]

Thanks! I've done it with LF356N Opamp from National Semiconductor.