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LP2951: error output

Jonathan Navor
Expert 7815 points
Part Number: LP2951

Hi TI team,

We need your help to check our customer's concern regarding the LP2951 "error output".

I will use lp2951 as power supply for my microcontroller.And my vcc 5V lp2951 has "error output".if the voltage drops to 4.75v and below "error output" will be low. I want to use my microcontroller only when the error output is not low. So I think I must correctly connect the error output to the reset pin of my microcontroller.

1)Which circuit should I make this connection with. Can you share a circuit diagram?

2)Does the lp2951 automatically turn itself off if it overheats?

3)If the input is 25Vdc and the output is 5Vdc, how many mA of current can I take continuously? What about If the input 20Vdc and output 5V,current?

Thank you so much in advance for the support. 

Kind regards,

Jonathan

  • 0
    TI__Mastermind 23361 points

    Hi Jonathan, 

    1)Which circuit should I make this connection with. Can you share a circuit diagram?

    Your understanding of how the ERROR pin works are correct but for the microcontroller connections question, depending on which one you use, I would suggest you post the question on the microcontroller forum and get better support there.

    2)Does the lp2951 automatically turn itself off if it overheats?

    Yes, the device will shut down the pass-FET of the output during an overheat event to protect itself. But for thermal shutdown, the output will not be latched off, which means the device may cycle in and out from thermal shutdown which will result in an ERROR pin toggling as well. 

    3)If the input is 25Vdc and the output is 5Vdc, how many mA of current can I take continuously? What about If the input 20Vdc and output 5V,current?

    The junction temperature can be determined using the junction-to-ambient thermal resistance (RθJA) and the total power dissipation (PD).

    PD = (IGND+ IOUT) × (VIN – VOUT) (7)

    TJ = RθJA × PD + TA

    To calculate the maximum DC current, you will need to specify a ambient temperature and use 125C as the maximum junction temperature. 

    Regards, 
    Jason Song