• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 47 subscribers
  • Views 489 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.

INA333: Part failures , max output sourcing current problem?

G S1
Prodigy 50 points
Part Number: INA333


We have has several INA333's fail on us where they are no longer outputting voltage and vcc to gnd is low resistance when using the same topology.

Two potential things we are violating in the datasheet.

1. I can't seem to find a max output current spec for this amp. We have the output going through a lowpass r=10ohm and c= 330pF filter before it hits an ADC. Could the parts be failing because every turn on the cap briefly pulls 0.120 A to charge from zero? We could increase R to prevent this but the datasheet says something bogus like Absolut Max rating: Output short-circuit = Continuous for both min and max?

2. Our Vin+ terminal comes up before the V+ and V- Rails supply power to the chip. The inputs are current limited to a milliamp and the input to the ina333 should be high impedance so I don't think this would be an issue.

  • 0
    TI__Guru 68171 points

    1. There is nothing bogus about allowing continous short-circuit  - see below.  Thus shorting the output to ground will not damage the part.

     

    Allowing Vin to come up before V+ by more than 0.3V will violate the Absolute Maximum Ratings - see below.  For that reason, in order to prevent damage to ESD protection diode between the input and postive rail, you must place a resistor in series with VIN+ to limit the input current to 10mA or less.