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SN74AHC14: Low input capacitance schmitt triggers

Part Number: SN74AHC14
Other Parts Discussed in Thread: SN74AUP1G14, , SN74AUP3G14, SN74AUC14

Hi,

I'm currently working on a discrete board that uses schmitt triggers inverters to oscilliate the electrode signal from a capacitive touch display. My goal is to minimize the stray capacitance. I wonder if there's a selection of schmitt triggers that can guarantee lower than a maximum of 10pF on the input of the schmitt trigger. So far I've been using the SN74AHC14N but want to know if there is any options.

Best regards,
Victor

  • Hi Victor, and welcome to the forums!

    We don't fully characterize input capacitance on logic devices, so there's no 100% guarantee, but the lowest input capacitance Schmitt-trigger inverter that I know of is the SN74AUP1G14.  It's typical input capacitance is in the 1.5 to 2pF range. It will also consume far less power than the SN74AHC14. Unfortuantely, there's no hex version of the device.

    If you're looking for one with multiple channels, perhaps the SN74AUP3G14 (triple ST inverter) would work.

    You could also try the SN74AUC14 -- it has a typical input capacitance around 2.5pF.