Inquiry regarding suggested input capacitance on SN74AHCT86

Atsushi Okui

Genius 4015 points

Other Parts Discussed in Thread: SN74AHCT86

Hello, all

Now we have one inquiry regarding suggested input capacitance on SN74AHCT86 from our customer.

Please refer to the item below, and feedback us with your comment.

We would like to add capacitor in front of A/B pins on this device in order to have noise robustness.

On this case, please let us clarify whether you have some suggested input capacitance for this device.

If you don't have, we would like to add 0.1 to 0.2 uF.

We thank you in advance for your information.

Best regards,

over 9 years ago

0 Chris Cockrill over 9 years ago

TI__Mastermind 46480 points

We do not have a recomendation for additional input capacitance. 0.1uf or 0.2uf are typical values we would use to filter noise so I beleive that would be OK.

0 Gabor Szakacs over 9 years ago in reply to Chris Cockrill

Intellectual 420 points

0.1 to 0.2 uF is actually quite large for filtering the data inputs to a gate. These values are more typically used on the power supply. Filtering the logic input signals usually requires much smaller capacitance. The actual value depends on the impedance of the circuit driving the inputs of the gate, as well as the frequencies you want to allow through and those you want to suppress.

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Inquiry regarding suggested input capacitance on SN74AHCT86