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UCC27511: OUTL absolute max voltage

Part Number: UCC27511

Hi Guys

Our customer is using our UCC27511 as low side mosfet drivers. But about the system test, we found sometimes there is -2.4V at OUTL pin.

Please see below waveform:

CH4: Pin3 to GND. you can see there is -2.4V between pin3 to GND. and pulse time is around 4.4ns.

I also see that our absolute max negtive voltage at OUTL pin is -2V and less than 200ns in our datasheet. But could you help evaluate whether there is any risk about customer's application? how do we optimize our application to make it less?

Thanks

-Vincent

  • Hello Vincent, 

    Thanks for your help promoting our drivers.

    For the very short pulse durations there are several considerations:

    a. High dV/dt narrow voltage spikes should be captured using very short connections probe set up and low setup capacitance on the probed nodes. In many cases the narrow spikes are not as high as recorded. Please confirm that customer is using tip and barrel method to capture waveforms.

    b. The driver's output stage is robust to withstand narrow pulse (<=10ns) as inductance of the bond wires will not allow for any significant current to occur in the internal driver FET device body diode.

    c. Voltage spikes of this duration will not have significant energy content.

    To optimize, please verify that:

    1. customer is using tip and barrel method to capture waveforms.

    2. decoupling capacitors are placed directly across driver's pins.

    3. short and wide PCB trace length between OUTx pins and gate.

    Please let us know if you have additional questions or press the green button if this addressed your question.

    Regards,

    -Mamadou