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TPS22967: TPS22967 RON vs load current

Eric Barbault
Prodigy 50 points
Part Number: TPS22967
Other Parts Discussed in Thread: CSD18511KCS, , TPS22975

Hello,

I'm looking for the Ron vs Iout curve.

I'm little bit surprise that there is no such curve on  any tps22xxx datasheet I saw.

The only RDSon value if for a Fixed value (200 mA  only) . But no clue on what happen on higher current.

 In order to justify my design, and guarantee a minimum voltage on the targeted device, I need  the Ron value for other  load currents or at least the Worst case in 0-4 A  over temperature range.

How I can get such data?

Best regards

  • 0
    TI__Mastermind 32650 points

    Hi Eric,

    Please use the data available on the electrical characteristics table. The specified max ON resistance is over the recommended operating condition and this includes variability over temperature and load current. The max R_on for this device is 35mOhm under recommended operating conditions.

  • 0 in reply to Shreyas Dmello
    Prodigy 50 points

    hello the electrical spec is for 5V bias

    :

    So

    So for Ron measurement test condition is specified : Iout -200mA & Vbias 5V,   that's means  it's not applicable for all current range.

    regards,

    Eric

  • 0 in reply to Eric Barbault
    TI__Mastermind 32650 points

    Hello Eric,

    The amount RON changes is dependent on the amount heat the unit sees. This could be due to high ambient operating temps or self heating of the die. The maximum R_on is spec'd accounting for this. 

    We also spec the max R_on at the minimum recommended bias of 2.5V for this part. Apologies, I referred to the 5V bias table instead of the 2.5V bias but event with the minimum allowed Vin at the minimum allowed Vbias over the full course of ambient temperature operation, the max R_on is 40mOhm.

  • 0 in reply to Shreyas Dmello
    Prodigy 50 points

    Hello,

    I well understand Ron value change, and also get that we can bias at different voltages.

    But what I want is at least a Ron vs  bias  @ temperature given value and  Max load (here 4A) not at a light load.

    For this part the max load id 4A and Ron is only specified à 200mA

    In fact I want such figure we can get for any power MOS like below for CSD18511KCS :

    Without Ron @  my current load use  (or @ least max current capability), I can't make provision of the voltage drop due to this Ron in my design , so prevent me to use such part.

    Br,

    Eric

  • 0 in reply to Eric Barbault
    TI__Mastermind 32650 points

    Hi Eric,

    We define the R_on with respect to the ambient and junction temperatures seen during use.

    This covers the situation for various load currents as higher load currents would lead to higher temperatures. I believe your worst case Ron will be 40mOhm.

    I would also recommend you to test your use case with TPS22967 with the help of our EVM to check if the system behaves as expected. You can find the EVM here: https://www.ti.com/tool/TPS22967EVM-023  

    We also offer TPS22975 which is a P2P replacement with lower R_on, lower cost and integrated thermal shutdown.

    Thank you for choosing TI Load Switches in your designs.