SN74LV123A: Confirm /A connection

Hung Ching Hsu

Part Number: SN74LV123A

Hi Team,

My customer is using SN74LV123A, only input B is used and the condition is L and ↑. /CLR pin is H.

Is it correct that input /A should be L to fulfill both L and ↑ for input B?

If so, customer will connect /A to GND, should customer connect it directly to GND or should he add a resistor? Either way, could you also explain why?

Thanks.

Regards,

over 3 years ago

+1 Clemens Ladisch over 3 years ago

Guru 316640 points

Yes; for a rising edge trigger, set /A = low. Also see [FAQ] How do I configure a monostable multivibrator's inputs for rising/falling edge triggering?

CMOS inputs can be connected directly to GND (or V_CC). You would need a pull-down resistor only if you wanted to change this input while debugging your board.

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SN74LV123A: Confirm /A connection