Reset Supervisor

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Sambuchi
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Reset Supervisor

Post by Sambuchi » Tue Feb 09, 2010 11:47 am

Is there a chip that can monitor a reset line so if the line is active low for 1ms... it will latch low till a reset is given to it?

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haklesup
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Re: Reset Supervisor

Post by haklesup » Tue Feb 09, 2010 3:25 pm

I suppose A JK flip flop with an RC network on the input would be the simplest implementation. This would work for "at least 1ms" and not "exactly 1ms". Short pulses cannot charge the C to the input threshold in time. Longer pulses allows the pin to charge to the threshold voltage.

dobrien
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Re: Reset Supervisor

Post by dobrien » Tue Feb 09, 2010 6:14 pm

You can use a Dual Retriggerable Resettable Monostable Multivibrator (One-Shot)
such has a 96L02 or equivalent.

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Bob Scott
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Re: Reset Supervisor

Post by Bob Scott » Thu Feb 11, 2010 8:56 am

dobrien wrote:You can use a Dual Retriggerable Resettable Monostable Multivibrator (One-Shot) such has a 96L02 or equivalent.
Wow. Sorry to interject, but I have never heard of the 96XX family of TTL. What difference does the 96 family have and were they specialty devices like military or something?

The reset latch could be so simple. Even a RS flip-flop would work, made from a pair of nand or nor gates, from a logic family that is compatible with your reset line.
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Robert Reed
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Re: Reset Supervisor

Post by Robert Reed » Thu Feb 11, 2010 1:15 pm

9600 series were popular in the 70s-80s. Were a line of common logic chips and were succeeded by the C-Mos chips. I believe they are still available in Asian markets. But I don't understand how a one shot would work as a latch?

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