SN74LVC1G74: Button Circuit Design

Allan Fan

Part Number: SN74LVC1G74
Other Parts Discussed in Thread: SN74LVC1G17,

Hi Expert,

Customer has a power button application and refer to SN74LVC1G74 datasheet fig.4 with buffer SN74LVC1G17. Do we recommend must to have the buffer?

Could you also share the design consideration for the buffer?

Thanks.

Allan

0 Dylan Hubbard over 6 years ago

Hi Allen,

0 Clemens Ladisch over 6 years ago

Guru 322000 points

The RC circuit results in a slow rising edge, which is likely to violate the Δt/Δv limit and thus could lead to oscillations on the CLK signal.

The buffer has a Schmitt-trigger input, which can handle the slow edge.

0 Allan Fan over 6 years ago in reply to Clemens Ladisch

Thank you guys.

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