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REF30: Over current failure mode

Joyce Gao
Intellectual 2870 points
Part Number: REF30

Tool/software:

Hi expert,

If the REF33 input current is continuously ~36mA (>datasheet recommending 25mA load current), or even higher current to damage the device, whether it will output 0 (short to GND) or become a high impedance output?


Joyce

  • 0
    TI__Intellectual 2870 points

    And what's this 'continuous' meaning? Is it meaning even shorted to GND at output, the device is in no risk of damaged?

  • 0 in reply to Joyce Gao
    TI__Expert 8590 points

    Hi Joyce,

    Can you confirm which device we are talking about? Your post is titled REF30, but you mention REF33 in the content of the post. The datasheet capture seems to be from the REF30 datasheet, so for my response to your query, I will assume you are asking about the REF30 device. Please correct me in your response if that is incorrect.

    Joyce Gao said:
    input current is continuously ~36mA

    What is meant by input current? REF30 has an output current maximum of 25mA. Anything greater than that will cause the device to fall out of datasheet specifications and potentially damage the device. We cannot guarantee correct device operation with a load current greater than 25mA.

    The short circuit specification can be seen in the EC table on page 6 of the REF30 datasheet:

    This is the amount of current REF30 will typically source when shorted to ground. This is different than the load current maximum of 25mA, and my recommendation to not exceed 25mA load current still stands.

    Do you need a device that can source greater than 25 mA? If so, what is the load of the voltage reference that draws so much current, and what is the end equipment?

    Thanks,

    Jackson

  • 0 in reply to Jackson Wightman
    TI__Intellectual 2870 points

    Hi Jackson,

    1. The asking is for REF30. 33 is a typo.

    2. I think you didn't get the question. To be simplified, if there is a very high current (you could ignore the value of 36mA or any specific value) at the input of REF30 that damaged the device, will the device be damaged to perform as shorted to GND, or open circuit that become high impedance?

    Joyce

  • 0 in reply to Joyce Gao
    TI__Expert 8590 points

    Hi Joyce,

    Thank you for the clarification. If REF30 is damaged because of a high input current, we cannot guarantee the performance. 

    Thanks,

    Jackson

  • 0 in reply to Jackson Wightman
    TI__Intellectual 2870 points

    Jackson,

    What does this "continuous" mean?

    Joyce

  • 0 in reply to Joyce Gao
    TI__Expert 8590 points

    Hi Joyce,

    This means that when REF30 is connected in a short circuit to ground condition, the output current will be limited to 45 mA typically (the number reported in the electrical characteristics table):

    Thanks,

    Jackson