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Original question:

DRV3245Q-Q1: does DRV3245Q-Q1 support 24V and 48V system?

DRV3245Q-Q1: Increasing transient protection

Alan Gillespie71
Prodigy 50 points
Part Number: DRV3245Q-Q1

Hi,

I wish to consider the DRV3245-Q1 for an application where the supply voltage ranges from 12V to 28V. As this gate driver is rated max 45V, it is unsuitable for use at 28V due to the possibility of load-dump transients damaging the device.

Has anyone incorporated additional transient protection in the supply line to enable a lower-voltage gate driver (such as the DRV3245-Q1) to be used at higher voltages whilst ensuring it is safely protected from transients up to at least 60V?

Would the addition of TVS or similar devices on the input supply be sufficient?

Thank you in advance,

- Alan

  • 0
    TI__Mastermind 18981 points

    Hi Alan,

    Thanks for reaching out on this through the e2e forum -

    You are correct that in motor driver applications, it's important to have sufficient max voltage rating margin to anticipate overvoltage events from transients.

    • we typically recommend targeting 1.5x to 2x the voltage rating of your expected nominal operating voltage 
    • in safety-critical applications, guidelines suggest 2x the voltage rating 

    There are cases in which the system designer can implement their system with a very well-conditioned VM/Vdrain bus to not fully meet this requirement

    • Question: what is your intended application with this DRV3245-Q1 device? 

    Some of the things that can be done to reduce the risk of transients are: 

    1. optimize the schematic to include sufficient bulk capacitors and bypass capacitors, and then configure the PCB layout to place these bypass caps close in proximity to the MOSFET power stage VDRAIN and also the DRV device's VM/PVDD supply pin 
    2. include HS and LS RC snubbers at the MOSFET SHx node to help filter out transients from the motor voltage 
    3. implement a battery management system for the VM/Vdrain bus 

    Some additional resources to consider: 

    Best Regards,
    Andrew 

  • 0 in reply to Andrew Liu
    Prodigy 50 points

    Hi Andrew,

    Thank you for you feedback and the useful links.

    Our application is an aircraft fuel pump and I would deem it a safety-critical application so x2 voltage factor is appropriate (>= 56V).

    You did not mention the use of TVS and I wonder if these could be used, in conjunction with a good supply conditioning strategy?

    In light of your comments, I am tending towards specifying a higher voltage gate driver.

    Kind regards,

    - Alan

  • 0 in reply to Alan Gillespie71
    TI__Mastermind 18981 points

    Hi Alan, 

    Understood on the situation, and appreciated on sharing the application context. 

    Quick question: what's the timeline you're looking at in terms of finalizing your design and ramping the production manufacturing? 

    • I will check within the team to see if there are any other safety-oriented gate driver devices that we can recommend, which have a higher abs max voltage rating (56V or higher) and similar feature-set. 
    • will consider some existing released devices, as well as maybe some of other upcoming devices depending on your project timeline 

    A TVS diode does have use in this case, since it can help give high voltage transients a path to dissipate through ground. 

    • I usually think of this as part of the power supply conditioning strategy for VDRAIN bus, so I didn't make an explicit separate mention of it 
    • But it is definitely applicable in your need-case 

    Best Regards, 
    Andrew

  • 0 in reply to Alan Gillespie71
    TI__Mastermind 18981 points

    Hi Alan, 

    Quick note on this - looks like we currently have some ongoing discussion via email w/ Issac Hsu about alternative options for DRV3245-Q1 with high voltage rating. 

    • Issac and myself would be the correct contacts for this - so let's continue the discussion through email, since some of the details on product timelines may be sensitive information. 

    Best Regards, 
    Andrew