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TPS1H000-Q1: minimum on-state resistance?

JLA
Intellectual 2545 points
Part Number: TPS1H000-Q1

Hello,

My customer is asking about the on-state resistance. It is specified on page 5 in datasheet.  For some reason there is no value for minimum on-state resistance. They need that to calculate the maximum output voltage at a certain load current and for that they need the minimum on-state resistance. Is there any estimate you can give me?

Best regards/Jorgen

  • 0
    TI__Expert 3575 points

    Hi Jorgen, 

    The Ron resistance of the MOSFET is given based on the Vgs voltage (after other parameters such as W and L are specified). Once the MOSFET has fully turned ON, the resistance seen is typically the minimum resistance. In the case of the High Side Switches, since the user cannot change Vgs directly, the resistance seen when the switch is ON will be the minimum resistance. For the case of the TPS1H000-Q1, the minimum resistance is 1ohm.

    If this answers your query, Please click "This resolved my issue" button.

    Sincerely,

    Francisco Lauzurique 

  • 0 in reply to Francisco Lauzurique
    TI__Intellectual 2545 points

    Hi Francisco, 

    Will negative temperature have any impact on the minimum on resistance?

    Best regards

    Jorgen

  • 0 in reply to JLA
    TI__Expert 3575 points

    Hi Jorgen, 

    Yes, extremely low temperatures will decrease the Ron of MOSFETs. However, more factors are to be taken into consideration here. 

    Follow up Questions:

    1- What will be the ambient temperature? 

    2- What are the load characteristics that the customer will be using? Voltages and Current 

    Sincerely, 

    Francisco Lauzurique 

  • 0 in reply to Francisco Lauzurique
    TI__Intellectual 2545 points

    Hi Fransisco, 

    1 – Ambient temperature is -40°C ... +85°C 

    2 – Supply voltage for TPS1H000-Q1 is 5V±2% and load current is 0…100mA

    Best regards

    Jorgen

  • 0 in reply to JLA
    TI__Expert 3575 points

    Hi Jorgen, 

    Thank you very much for the extra details. The following image can be found on page 8 of the datasheet. If you are using the lowest possible temperature then the device Ron resistance will decrease by a max of 0.2Ohms.

    I believe that in addition to this factor, you should consider the heat emitted by the device itself when dissipating power. I am uncertain about this assumption, but I will go ahead and do a deeper investigation here. I will have you a certain answer by end of today. However, looking at the loading values you have provided me, this would not make a significant difference. 

     

    If this answers your query, Please click "This resolved my issue" button.

    Sincerely, 

    Francisco Lauzurique 

  • 0 in reply to Francisco Lauzurique
    TI__Expert 3575 points

    Hi Jorgen, 

    As a follow-up, for the Ron resistance in this case, if looking for the worst-case scenario, you will be using your ambient temperature only. Thank you very much for reaching out here.  

    If this answers your query, Please click "This resolved my issue" button.

    Sincerely, 

    Francisco Lauzurique