• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 19 subscribers
  • Views 132 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN74LV14A: Output current rating

Taku Murayama
Intellectual 820 points
Part Number: SN74LV14A

We plan to change the constant of the damping resistance at the output destination on the current board.
As the output current increases, the peak current flows about 44 mA (1 μ or less) in a period of 10 to 20 μ.
(There is no problem at all with the actual and average values of about 10 mA even in the range that looks quite large.)

it can be read as 25mA continuous output and 50mA maximum output according to the data sheet. Is it OK to use a peak current of 44 mA in 10 to 20 μ cycles?

  • 0
    Guru 244390 points

    You must never exceed the limit of 25 mA for a single output pin. 44 mA can damage the device. (The clamp current applies only to negative output voltages, which do not happen during normal operation.)

    Why is there such a large current? Are you shorting the output, or is there a large capacitor?

  • 0 in reply to Clemens Ladisch
    TI__Intellectual 820 points

    The output is only slightly raised by lowering the resistance value of the gate resistance connected to it at the gate terminal of the FET, and nothing in particular is connected. (Terminal capacity of FET)

    It only appears as a peak for a moment when the logic output switches to H.
    On the datasheet, it is written that the continuous current is 25mA, and there is no running current or average current at all, but does that mean that it should not exceed 25mA for even a moment?

  • 0 in reply to Taku Murayama
    TI__Genius 12000 points

    Hi Taku,

    No, TI cannot guarantee or characterize operation outside of recommended operating conditions and you are at risk of damaging the device if you exceed the absolute maximum ratings in any capacity.

    There are some situations where exceeding absolute maximum values would likely be ok and not effect device reliability or performance (for example, you are seeing >25mA for, say, 2-3 nanoseconds), although, of course, TI can make no guarantees. Our devices are quite robust and could operate despite the 50mA for 1us, however, you assume all of the risk if you choose to do so.

    My recommendation would be to choose an output damping resistor such that the current doesn't exceed what's on the datasheet.

    Best,

    Malcolm