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Finding a Gate Driver

Other Parts Discussed in Thread: UCC21520

Hi

I have this task. Find a gate driver that can to the job on the attached schematic.

The driver must not be making noise on the output-DC-signal - eg from refreshment of gate-chargement.

Do you know such a driver?0743.Sheet1.pdf

  • Hello Martin,

    I am an applications engineer for high power gate drivers.

    Are there any other requirements needed for the gate driver besides isolation?

    What is the part number of the FET being driven here?

    regards,
    Mateo

  • Hi Mateo

    Theres no special mosfet on the table. Just a "fast one" that can withstand about 500Vds. We use to built the gate drivers with a refreshment of the gate-charge - but this is a bit noisy for some applications.

    regards

  • Hi Martin,

    Take a look at the UCC21520. This is our dual-channel reinforced isolated gate driver.

    The refreshment of the gate-charges comes from the boot-strap configuration as shown in figure 34 of the datasheet.

    With this bipolar operation pay close attention to the max and recommended values for VDDA-VSSA, OUTA-VSSA, VDDB-VSSB, and OUTB-VSSB.

    Regards,
    Mateo
  • Hi Mateo - thanks for the advice.

    I will try it out.

    I did not know it could run with negative rail as well.

    regards

  • Hi Mateo

    Which kind of power supply can be used for the gate-driver?

    I would prefer a linear to avoid switch mode noise.

    However in my test setup a linear lab supply seems to be to slow.

    regards Martin

  • Hi Martin,

    We typically care more about the bypass capacitors and how close they are to the IC than the types of power supplies used as the IC's VDDA, VDDB, or VCCI.

    From the datasheet's power supply recommendations:

    A local bypass capacitor should be placed between the VDD and VSS pins. This capacitor should be positioned
    as close to the device as possible. A low ESR, ceramic surface mount capacitor is recommended. It is further
    suggested that one place two such capacitors: one with a value of between 220 nF and 10 µF for device biasing,
    and an additional 100-nF capacitor in parallel for high frequency filtering.

    Similarly, a bypass capacitor should also be placed between the VCCI and GND pins. Given the small amount of
    current drawn by the logic circuitry within the input side of UCC21520, this bypass capacitor has a minimum
    recommended value of 100 nF.

    regards,
    Mateo