ADS8684: rise and fall time RST/PD signal

Lutz Naumann

Part Number: ADS8684
Other Parts Discussed in Thread: ISOM8110

Tool/software:

Dear team,

we want to control the RST/PD pin via optocoupler. The fast reset within <100ns can be excluded then. We are talking about the >400ns power down as the opto pulse will be in the 10us+ range. Having this said, is there a rise and fall time requirement to the RST/PD pin? Can we do this via optocouplers?

thanks

Lutz

3 months ago

0 Tom Hendrick 3 months ago

TI__Guru**** 181001 points

Hi Lutz,

I am not aware of any dV/dT restrictions on the RESET/PD pin. A 10uS pulse should be OK, so long as the rise time is reasonably fast (i.e. <2-3mS).

0 Lutz Naumann 3 months ago in reply to Tom Hendrick

TI__Expert 6460 points

Thanks Tom,

for the rise time do you mean 2-3us or really 2-3ms? This would be quite long for the 10us pulse... Our opto emulators ISOM8110 is more the 2-3us type and I would expect the same for other optocouplers.

Lutz

0 Tom Hendrick 3 months ago in reply to Lutz Naumann

TI__Guru**** 181001 points

Hi Lutz,

I was trying to think of something that might cause issues, which is where the mS came from.

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ADS8684: rise and fall time RST/PD signal