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LM5113: Reverse Recovery Losses for Bootstrap Diode

Deepak Gunasekaran94
Prodigy 10 points
Part Number: LM5113

Hi!

I am interested in using the LM5113 bootstrap driver for my design. Upon checking the datasheet, I came across the plot showing the reverse recovery losses in Figure. 19 of the datasheet.

http://www.ti.com/lit/ds/symlink/lm5113.pdf

Per the plot, the loss is about 50 mW at a switching frequency of 200 kHz. This seems odd to me (seems too large!). 

According to Table 6.6, the bootstrap diode has a trr of 40 ns at I_F and I_R of 100 mA.

The following are my questions:

1. Does I_R imply the peak reverse recovery current (I_RR) ?

2. If so, is the plot in Fig.19 based on the same I_RR and t_rr values ?

3. If not, what are the test conditions (peak reverse recovery current and trr or Qrr) used for the plot in Figure 19 ?

Thanks

  • 0
    TI__Intellectual 2910 points

    Deepak,

    Thank you for your interest in the LM5113 GaN driver. Regarding your three questions:

    1. Yes, my understanding of this test condition is that it refers to the peak I_RR getting to 100mA

    2 & 3. The determining conditions for the plot in Figure 19 is that the load of the high-side driver is a GaN FET with total gate charge of 10nC and that the bus voltage of the half-bridge is 50V. The data I have available does not include peak I_RR for this test. The t_rr parameter from Table 6.6 and this plot from Figure 19 should not be assumed to be at the same test conditions.

    I hope this post answers your questions. If it does, please press the green "Verify ANswer" button below.

    - Daniel