ADuM4135 Output Buffer

I am thinking of a combination of ADuM4135 and SiC MOSFET.
Since the output current of ADuM4135 is insufficient, we are considering adding a buffer.
Do you have a reference circuit or application note for ADuM4135 + buffer?

  • +1
    •  Analog Employees 
    on Feb 18, 2021 7:47 PM

    Hello,

    I don't have a reference circuit readily available for the ADuM4135 + buffer, but I am curious what gate charge and rise times you are hoping to achieve. The ADuM4135 is marked as a 4 A driver, but the 4 A is not the short circuit peak current, but rather a typical use case value. You can use the driver with a peak current higher than 4 A if desired. Is this SiC device a large module?

    If using an external buffer, the main concerns become interfacing with the soft-shutdown and connecting the Miller clamp. Connecting the Gate_sense pin to the SiC device gate is recommended. If a desat fault is detected, and soft-shutdown is entered, the buffer stage would most likely result in a normal strength turn off, but shifted by the prop delay of the buffer stage.

    RSchnell

  • Hello,

    A peak current of about 8A is assumed.
    SiC : Qg = 1150nC, Internal Resistance = 1.2ohm , External Gate Resistance = 1ohm

    I expect a fast rise time.

    Gate_sense pin connects directly to the gate of the SiC device.
    I think that the mirror clamp function works normally.

    Thank you.