DRV401: DRV401

Hello user5272063,

Is there any way you can share some more details on your design such as schematic.  Have all your devices failed?  You could be damaging the Vref pin somehow.  When do your devices show this behavior?  Is it always or after testing?

hello!

Thank you for your reply, The schematic as follows. The voltage between R2 and R3 is about 0.

5V, We hope the Vout can be 4.5V (2V+Vref).

Not all devices failed,  We tested about 20 pcs devices, there are 3 pcs devices failed after the test .

Best regards.

Hello,

Thanks for sharing your schematic. Is there any pretest involved or is just assembly and test? Is R1 330Ω? Can you measure the voltage drop accross it. I would just like to know if the problem is with RefIN or RefOut.

How is it you are testing it? Also with manufacturing I see you are using the QFN package how do you have these boards manufactured? Is there any possible shorts on the bottom of the DRV401?

Hello,

I am sorry, there is some wrong with the schematic, the R1 is 680Ω，C3 is 180nF,  C5 is 1nF. The voltage drop accross R1 is about 0.3mV.

For the bad sensor, we found the DRV401 hot serious after power on.

There is no any pretest involed , we  just assembly and test the sensors, and we only test the Vout when primary current is 0A and 15A.

We use Auto SMT machine to mount the DRV401, and I don't think there is shorts on the bottom of the DRV401.

By the way, I am poor in English, especially at spoken-English,So I think email communication is more suitable for us. I hope you could understand.

Best regards,

Hello,

I will be looking into this to see what could be causing this.

A couple of things when you said the part gets hot. Can you tell if the additional current that is causing the part is going into the compensation coil, reference pin. You can see this by measuring across R1 for reference pin and across R2/R3 for the compensation coil current.