This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TLV62150: About the dead time period

Part Number: TLV62150

Hi,

I asked the maximum rating on the negative side of the SW pin in the following thread.
I understand that the inductor current flows during the dead time period.
This time, I would like to ask about that dead time.
Attach the measurement waveform. Measured waveform of SW pin.
Looking at this waveform, the negative voltage continues for about 30 ns. Is this a dead time?
If this period is dead time, why does it continue for 30 ns?
In addition, although this period of 30 ns is about -0.7 V, is it OK to think that there is no problem?

(Measurement condition)
VIN: 13 V
VOUT: 2.5 V
IOUT: 200 mA

Best Regards,

  • Yes, this does not violate any abs max spec (which are DC).

    Adding the inductor current to the waveform can help see where this comes from. I assume the time shortens as the load is increased?
  • Thank you for your reply.

    I also confirmed the inductor current.
    Attach a waveform. Increasing IOUT narrows the negative period.
    Also, in NO LOAD, a negative period occurs after switching.
    What is the cause of this negative period?

    Best Regards,

  • It seems that your current probe is not zeroed, as the current never reaches 0 (as shown on the y-axis).

    If we ignore this offset, we can see that the SW node goes more negative when there is still some positive inductor current flowing. This creates the more negative voltage: the current through the body diode. When this reaches 0, the body diode turns off and the SW voltage begins to ring to its DC value (at Vout). This is perfectly normal and acceptable.