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ADE7854A SPI SCLK Schmitt trigger input

Question asked by markushug on Jun 24, 2016
Latest reply on Jun 27, 2016 by dlath

Hi,

 

I have a question to the SPI Clock specifications of ADE7854A family.

 

In the Pin description (datasheet page 15), SCLK/SCL is described with:

Serial Clock Input for the SPI Port/Serial Clock Input for the I 2 C Port. All serial data transfers synchronize to

this clock (see the Serial Interfaces section). The SCLK/SCL pin has a Schmitt trigger input for use with a clock

source that has a slow edge transition time, for example, opto-isolator outputs.

 

But in the SPI Interface Timing section, the SCLK Rise and Fall Time are noted with 20ns maximum.

 

Having an optocoupler in the line (as I have), this rise and fall times are not easy to achieve. And for a Schmitt trigger, not necessary to be that fast, I would say.

So my question: can ADE7854A handle with rise times of 1µs? (I measured 880ns rise time and 48ns fall time. And it works well so far.)

 

Thanks for answering.

 

Best regards,

Markus

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