DRV3946-Q1: When OUT has normal output and a fault occurs, how does 3946 identify it

Hi,

You would be able to detect such a condition if this was during current regulation as you would see an OCP_LS:

Best,

Keerthi

We are currently short-circuiting the PVDD to cause a fault and then clearing it. However, when we issue the closing command again, it still fails to close the relay. We must issue the opening command first and then the closing command to restore the relay close.

Hi,

Is the short still present while trying close the relay or is this the sequence: remove short -> clr_flt -> close relay command.

Best,

Keerthi

Short circuit to the power supply, create a fault, the relay opens, then remove the fault, the relay does not close, issue a close command again, the relay still does not close. The relay can only close when the disconnection instruction is resent and the relay is controlled to close again. The fault has been removed.

Here is another question. At the OUT output terminal of 3946, the signal level is as shown in the following figure, and there is a situation of large and small waves. Is this output waveform normal？

Hi 

We can discuss during our meeting.

Best,

Keerthi

Hi, 

The output waveform can be expected if the DC > 50%. Could you tell me once the operating voltage, resistance of contactor and the peak and hold current regulation values that you are using?

Best,

Keerthi

The operating voltage is 12V, the resistance of contactor is 24Ω, the peak current is 400mA, and the holding current is 230mA