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Clock source for a smartcard help a bit please

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TKS

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I have not much expierience with this kind of stuff

soow hope some one can help.

They use in this schematic as Clock a 74HC00

well i have in stock a 74HC04N and an SN7407N

can i use one of them?? and how do i need to hook it up?

i have realy no idea how they work

Regards,

TKS
 

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ok, i don't study electronics, its a hobby from mine.

but can you tell me if its possible with them??

do i only need to look at the symbols an look for the combination in the others?

TKS
 
Ok

Is it true that

i can use the 04 one??

the only difference is the quantity of pins i conect to the Crystal??

the 00 uses a & gate put outputs inverted the 04 is only an inverter..

but because of the fact that both are conected together the & isn't working soow is it true i can use the 04 one??

TKS
 
Use only one input of HC00 - this give smaller load - and connect the another input to Vcc.Be sure, the gate input connected to Xtalout pin.
 
uhhh

its a well famous (not) Nut Chip???

I have hooked up it with my 74HC04

and he is giveing a cloksource to the card.

but i stil have the feeling that there is a little difference....
because sometimes it works and sometimes not.

(giveing acces to the main system)

today will do some more testing with it.

in the article also states that from the 74HC... its better to connect al pins to ground wich you don't use (inputs) is that true??

TKS
 
Re: uhhh

TKS said:
its a well famous (not) Nut Chip???

I have hooked up it with my 74HC04

and he is giveing a cloksource to the card.

but i stil have the feeling that there is a little difference....
because sometimes it works and sometimes not.

(giveing acces to the main system)

today will do some more testing with it.

in the article also states that from the 74HC... its better to connect al pins to ground wich you don't use (inputs) is that true??

TKS

Try it with a 40-series CMOS gate, to further decrease the load on the crystal, and yes all unused inputs should be connected to ground or V+. Floating inputs start 'toggeling' on their own causing switching currents.
 
any

example chip??

pff

i dunno looks like my incoming voltage is realy really dirty..

will check conections etc.

TKS
 
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