IC informaiton

[BTDe]

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

 

[akg]

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

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

 

[BTDe]

IC info

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

 

[Nigel Goodwin]

Re: IC info

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

'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!.

 

[ljcox]

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.