CD74HC123: cd74hc123 quick qeustion

Sulyn ZHANG

Part Number: CD74HC123

Hi Team,

I have a quick question about CD74HC123. he calculation for the pulse width is tW = 0.45 RXCX at VCC = 5V. as described in datasheet.

So how about the formula for this pulse width at VCC=3.3V? The same one or something different? My customer need to use 3.3V supply

Thanks a lot for your support!

Best regards,

Sulyn

0 Karan Kotadia over 5 years ago

Hi Sulyn,

Let me get more information on this. I will get you an answer by the end of the day.

Thanks!
- Karan

0 Karan Kotadia over 5 years ago

Hey Sulyn,

The equation to calculate the pulse width is Tw = K*Rx*Cx

The value of K changes with Vcc. This change can be found on the following plot in the datasheet.

So at 3.3 V your equation should be about tW = .48*Rx*Cx

Thanks!

- Karan

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