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LM25145: Gate driver settings and ILIM pin ratings

Kaji@PAN
Mastermind 7805 points
Part Number: LM25145

Hello,

I am an FAE for a distributor that handles TI products.
The customer asked me about the LM25145.
(Question 1)
Is it possible to configure the HO pin and LO pin as shown below?
Adding gate resistors and pull-down resistors
*In the data sheet, there is a description of inserting a resistor into the BST pin, but I would like to consider the gate resistor as well.
Nch-MOSFET connected in parallel, FET is SMD type or TO-220 type
(Question 2)
Is it possible to connect a gate driver to the HO and LO pins?
(Question 3)
The maximum rating of the ILIM pin is -1V (MIN) and the data sheet describes it.
20ns-transient is additionally stated for the SW pin, but does the ILIM pin have that condition?
I'm concerned if the change in the ILIM pin can be kept within -1V.

Best regards,

  • +1
    TI__Mastermind 22301 points

    Hi Kaijin,

    Yes this is possible to drive dual FETs with the gate driver.

    It will put more load on the gate driver, so you may see slower overall rise times. Be careful of FETs with very large QG.

    We dont recommend gate resistor for LO, lowside FET needs a strong pulldown to prevent MOSFET CdVdt self turn on.

    You can also use a pulldown diode if you absolutely need a gate resistor for LO.

    You can use an external gate driver, you will have to GND SW node and then need to use shunt resistor current sensing.

    The ILIM should have the same tolerances as SW, however note that R-C filter on ILIM should filter those 20ns SW transients.

    Hope this helps,

    -Orlando