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TXRX

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Hi,

I want to memorize the state of a switch, see attached schema, i connect DFF from ON-SEMI pn:NL17SZ175DBVT1G to the switch, the D input will move to Q output at rising-edge of CONTROL signal CP, i dicide also to connect /C input to CONTROL input in order to insure the Q=0 when CONTROL=0.

Is it must to do time delay the CP input AFTER /C input like the graph at page 6 on attached data sheet ? , I connect both of them to CONTROL signal in order to save components for delay circuit.
 

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  • NL17SZ175DBVT1G.pdf
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Hi,

Is it must to do time delay the CP input AFTER /C input like the graph at page 6 on attached data sheet
Don´t look at a graph. They usually are not to scale.
Look into the timing specification "AC ELECTRICAL CHARACTERISTICS"
--> trec = Recovery Time, /C to CP

I don´t know whether this gives the expected "memorize" function.

Did you check `373 Latch function?

Klaus
 

'373 Latch is Octal and big IC i need only 1 DFF.
--- Updated ---

The Recovery Time: /C to CP for pn:NL17SZ175DBVT1G acc. the data sheet is minimum 1nSec over temperature, So it is look that i need to add RC circuit at CP Input.
 
Last edited:

'373 Latch is Octal and big IC i need only 1 DFF.
--- Updated ---

The Recovery Time: /C to CP for pn:NL17SZ175DBVT1G acc. the data sheet is minimum 1nSec over temperature, So it is look that i need to add RC circuit at CP Input.
I add resistor of 20K to CP Input (The Capacitance is 2.5pF) so it will give Recovery Time of around 34nSec.
 

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