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TPS65381A-Q1: How to Configure TPS65381AQ1 for more current rating??

Saravanakumar S93
Expert 1300 points
Part Number: TPS65381A-Q1

Hello All,
Currently, we are developing the safety critical product.
Our DC/DC convertor supplies the below supply voltage/rating = 12V DC/2 Amps.
But, the TPS65381 AQ1 will give 1300 mA maximum. We are planning to take the power for all other ICs's via TPS65381 AQ1.
Since, TPS65381AQ1 has less current rating. How to enhance the current ratings from 1300 mA to 2000 mA ?
As a part of safety measure, along with TMS570 microcontrollers, other IC's power also can be shared via TPS65381AQ1. Is this approach OK?

Regards,
S.Saravanakumar

  • 0
    TI__Genius 9655 points
    Hello Mr. Saravanakumar,
    I assigned your request to the expert, but due to the thanks-giving-week in US, there may be a delay in the response. Please accept our apologies for this.
    Since the internal FETs of the IC are the components that limit the current, it's unlikely that the output current can be increased. Potentially, the TPS65381A-Q1 could be used to MONITOR an external supply and thus maintain functional safety needs?
    Best regards,
    Frank
  • 0 in reply to Frank Dehmelt
    Expert 1300 points
    Hi Mr. Frank,
    Thank you for the quick response.
    Yes. I agree TPS65381A-Q1, mainly used to monitor to provide the external supply.
    This IC provides 3.3 V dc and 5V dc. We are planning to use 3.3V dc, 5V dc power supply for other IC's.
    The total current consumption will be 2000mA. Along with the external power supply monitoring, we want to use the output power supply from TPS65381A-Q1. This is the main intention.
    If it is possible, we can achieve the same via additional circuit along with TPS65381A-Q1.

    Regards,
    S.Saravanakumar
  • 0 in reply to Saravanakumar S93
    TI__Expert 8730 points
    Hi Saravanakumar,

    Are you saying that total current on VDD6 will be 2000mA? In that case, you may need to consider using additional high voltage BUCK in parallel with TPS65381A-Q1 device.

    If total current on VDD6 does not exceed its limit, you can use VDD6 as input to additional low voltage BUCK to generate additional rails.

    Regards,

    Murthy
  • 0 in reply to Krishnamurthy Hegde
    Expert 1300 points

    Hi Krishnamuthy,

    Thank you for the feedback.

    Since, there is no option available. I have proceeded with LDO regulator with cutoff option already.

    Regards.

    S.Saravanakumar

  • 0 in reply to Saravanakumar S93
    TI__Mastermind 20590 points

    Hi Saravanakumar,

    I do not think you fully understood one of the earlier posts.  The VDD1_SENSE pin of the TPS65381A-Q1 is used for two purposes:  VDD1 regulation loop feedback (sense) and VDD1 voltage monitoring (VMON) or the independent voltage monitoring function.   For MCUs that need more core current or other loads a parallel buck may be used, either cascaded from VDD6 (as a pre-regulator) or if the current and power needs are too high for the buck efficiency and total load on VDD6 for the TPS65381A-Q1 then the supply to the buck may be the main power supply such as the car battery or main 12V industrial supply.  The output of this buck is then used to supply this higher current rail while the VDD1_SENSE is used as the voltage monitor for this rail and the LDO controller VDD1 with external FET isn't used to regulate but only be the voltage monitor.  These concepts are shown in the attached PDF.

    2017-02-03 TPS65381A-Q1 with External DCDC.pdf

    Best Regards,

    Scott