SN74LVC1G99 input transition

Luke Trowbridge55

Other Parts Discussed in Thread: OPA4170, CD4516B

Hello,

I would like to use use the subject part to interface to signals that transition slowly (50us/V). I thought that Schmitt inputs would allow this, but the datasheet recommends < 5ns/V for 5V supply. Is this a mistake, or is there another recommended part?

Thanks,

Luke

over 8 years ago

0 ShreyasRao over 8 years ago

TI__Guru 56960 points

Hi Luke ,

This is a recommendation but I don't think this should apply for Schmitt trigger inputs . Schmitt trigger inputs are supposed to withstand slow and noisy signals into them .
what are you using this in the application for and how slow will the signal rate be?

0 Luke Trowbridge55 over 8 years ago in reply to ShreyasRao

Prodigy 20 points

OK, that's what I thought. The logic gate is to drive a level-sensitive (not edge sensitive) logic chip (CD4516B CARRY IN input). If the output goes indeterminate or toggles states quickly for a few microseconds, I don't care. I want to use an OPA4170 acting as a comparator to drive the input to this logic gate. I'm assuming that the minimum slew rate on this op-amp is 0.2V/us, providing an input transition rate of 5,000ns/V.

Luke

0 ShreyasRao over 8 years ago in reply to Luke Trowbridge55

TI__Guru 56960 points

Hi Luke ,

Schmitt triggers are suited for slow rising edge signals and I would recommend this here .

Logic

Logic forum

SN74LVC1G99 input transition