Switching time of 7408 IC... >21MHz?

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MM007
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Switching time of 7408 IC... >21MHz?

Post by MM007 » Wed Jan 10, 2007 12:38 pm

I'm trying to design an NES overclocking circuit, but part of the circuit design I am using requires a signal in excess of 21MHz to be fed through one input of a standard AND gate, spacifically a 7408 IC chip.

My question: Can the 7408 IC keep up with the clock signal and put out a signal of >21 MHz at its output?
Last edited by MM007 on Wed Jan 10, 2007 5:11 pm, edited 1 time in total.
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Post by codeman » Wed Jan 10, 2007 2:48 pm

huh? Why are you using a 7808 to output a clock signal? What exactly are you trying to do?

I dont think the 7808 would be fast enough anyway...
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Post by marshallh » Wed Jan 10, 2007 3:03 pm

I think you mean a 7408. Better to use a 74HCT08, the letters are for for "High-speed CMOS TTL compatible" so it runs at 5v. I'm pretty sure it can handle high frequencies, it's made for them.
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Post by gannon » Wed Jan 10, 2007 3:04 pm

If nothing else, a switching transistor based gate should work I think.

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Post by codeman » Wed Jan 10, 2007 4:50 pm

hahaha...that makes a lot more sense! I was wondering how you could make a clock signal with a 7808 regulator...
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Post by MM007 » Wed Jan 10, 2007 5:16 pm

Hmm...I'm using an "NTE7408"...and I've corrected the original post.

I may have to make some alterations then...hmm...
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