LMV393: When we used LMV393IDGKR, we found that the waveform output of the comparator was a little strange

Hello Gary,

Can you get a scope photo of the inputs at the same time? Preferably both inputs an the output on the same screen.

Do note that the LMV393 is not a rail-to-rail input device. The input limit is 0.7V below 3.3V, or 2.6V. So if there are any voltages greater than 2.6V on the inputs, there could be erroneous outputs.

Do you have a pull-up resistor anywhere? What is the output driving?

Hi Paul,

both inputs an the output on the same screen

FYI~

Hello Gary,

The "Glitch" just looks to be normal comparator "chatter" from a slow moving input signal. You do not have any hysteresis, so the output can "chatter" while the output moves through the threshold.

Please see this TI Design about Hysteresis:

Comparator with Hysteresis Reference Design

As an experiment, try adding a 100k to 470k resistor from the output to the positive input to add a little hysteresis.

Please see the following application note

Non-inverting comparator with hysteresis circuit (Rev. A)

You could also try using a TLV7042 which has built-in 10mV hysteresis.