• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 20 subscribers
  • Views 551 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

SN74LVC1G11 Not operating according to truth table

Isaac Vega
Prodigy 20 points

I have the SN74LVC1G11DCKR 3 input and gate. When pin 1 (input A) is high the output is high regardless of the state of the other inputs, even when grounded; also when pin 1 is high the chip begins to draw a significant amount of current for its size about 100mA @ 3.3 Volts VCC. Could someone please help me understand the issue with this part. I have tried replacing the part several times and tried different packages with no success, the part does not folow a typical 3 input AND gate truth table.

  • 0
    Guru 316470 points
    This sounds strange. How exactly are you testing this? In a circuit? Did you ever leave any input unconnected? Which packages? Are you really sure you've always identified pin 1 correctly?
  • 0 in reply to Clemens Ladisch
    Prodigy 20 points

    A couple of my co workers and I agree. We tried two different packages, DCK and DBV to be precise. Our test is as follows. The output is connected to a DMM. All the inputs are always connected to 5V in the beginning, we produce the truth table by switching from ABC  from 0 0 0 to 1 1 1. We tried re ordering the part, we read the datasheet entirely and nothing seems to explain this behavior.

  • 0 in reply to Isaac Vega
    TI__Guru 61940 points
    could you please send out the schematic , scope shots , anything which can be helpful in determining the root cause . is it on bread board or PCB ?
    100mA is way above the spec for the device . do you have the top side marking of the device too to confirm ?