SN74AHC595: Recommended max VIH

Johnny Guo

Part Number: SN74AHC595

Hi, team,

I have two questions about SN74AHC595 may need your help.

What is the recommended max VIH when VCC is 5V/3V/2V?

What is the recommended VIH min and max voltage when VCC=3.3V?

Thanks.

Johnny

0 Emrys Maier over 6 years ago

Hi Johnny,

The maximum input voltage is shown immediately below the V_IH and V_IL specs in your screen capture above, and it is independent of the supply value.

If you'd like to learn more about this spec, there's a great app note on the topic located here: Understanding and Interpreting Standard Logic Datasheets

The V_IH section is on page 28.

0 Johnny Guo over 6 years ago in reply to Emrys Maier

Emrys,

So do you mean VIL max is always 5.5V no matter VCC is 2V or 5V?
Thanks.

Johnny

0 Emrys Maier over 6 years ago in reply to Johnny Guo

Hey Johnny,

No, I mean that the VIH max will always be 5.5V no matter the supply value. The VIL min similarly will always be the same (0 V).

It's highly recommended to operate the part as close to the voltage rails as possible for the best results.

0 Johnny Guo over 6 years ago in reply to Emrys Maier

Thanks Emrys.

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