could someone tell me the difference between the 74LS90 and 74HC90, that is the difference between LS and HC type.

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BLUE
BTDe of NIMCOP
nakhanw@essex.ac.uk
bluenavz@yahoo.com
ONCE KNOW THYSELF

 

both denotes the type of components(eg: transistors) in the gate
LS is low power schottky device
and HC is a CMOS device

 

thanks, actually i wanted to use it in my frequency counter but do not know if it could count the frequency upto 150Hz. that is pulses coming are the rate of more that 20pulses per sec.
what do you think

__________________
BLUE
BTDe of NIMCOP
nakhanw@essex.ac.uk
bluenavz@yahoo.com
ONCE KNOW THYSELF

 

'Anything' could count frequencies that low, you could almost do it on your fingers and toes!. Standard TTL works up to something like 50,000,000 pulses per second!.

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PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Alternatively you could use a counter from the 4000 series CMOS range. These can operate from a much wider range of supply voltage than the 74LS and 74HC series.

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Len