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BoostXL-DRV8301

Paulo Neves
Intellectual 270 points
Other Parts Discussed in Thread: BOOSTXL-DRV8301, DRV8301, CSD18533Q5A

Hi

I would like some help understanding the parameters of the BoostXL-DRV8301 and its MOSFETs.


In the datasheet of BoostXL-DRV8301 it is stated in the features:

  • Supports 6 to 24 V and up to 10-A RMS (14-A Peak)

I have an application for a motor that requires peak 20A at 7.4V(startup). The way I see the statement is that the maximum power allowed for peak is in the worst case scenario = I*V =14*24=336W which is less than what I want 20*7.4 = 148.W. Is this interpretation correct, or I can't think like this.


In another question, I would also like to know what would be the gate drive voltage of the DRV8301 to the MOSFETs in the BoostXL board. This is important to know the RdsOn of the MOSFETs.


Also according to Figure 11 of CSD18533Q5A datasheet a 100% duty cyle would allow practically 0A to be driven when Vds > 10V DC. Doesn't this contradict the BoostXL datasheet of continuous 10ARMS (100% dc)? May be I am making some egregious mistakes so I would like to be corrected.


Thank you

Paulo Neves

  • 0
    TI__Mastermind 21320 points

    Hi Paul,

    The operating conditions are rough estimates based on our tests at room temp. The main limitation for power on this board are the amount of heat it can dissapate and the sizing of the power sense resistors. I think thermal dissapation would be ok for a startup transient but you will saturate the amplifiers which may affect the sensorless algorithm.

    The gate drive voltage can be found in the DRV8301 datasheet. It is typically 10V.

    I do not understand your 3rd question. Figure 11. specifies the amount of Drain-Source current at a given Drain-Source voltage.

  • 0 in reply to Nicholas Oborny
    Intellectual 270 points

    What I mean with the 3rd question is what is the drain to source current envelope, above or below the colored lines. I am not sure I understand it correctly.

    Regarding the power sense resistors. Do you think there would be problems in changing and resoldering the board resistors so that the amplifiers did not saturate, or are this resistors calibrated in the factory?


    Thank you for your help

  • 0 in reply to Paulo Neves
    TI__Mastermind 21320 points

    I think I understand the confusion. I am not entirely clear here either.

    From what I can tell this graph walks through the allowable current at a given Vds to stay within the safe operating area. I am unsure if this accounts for thermal dissaptation into the PCB or if the FET is solely isolated. You may be better off asking on the Power FET forums. We generally never operate at DC with a BLDC motor so it is never a concern.

    You should be able to replace the sense resistor if you can find one in the same package. I believe this would be the main limiting factor for you but cannot guarantee.