I have some problems with a AD8276 after some hours the circuit burns off.
the power supply is +/- 13 volts. The input signal does not exceed 10 volts and the load of the circuit in a 20kohms resistor.
do you have a explanation
Does the circuit work normally for several hours and then stop?
When you say "burns off", do you mean the part fails completely? (burns up?)
Do you have +/-10V on the inputs with no power supplies?
Under normal operation, does the part get hot?
Is this more than one pc board?
Yes the circuit works normally for several hours The part doesn't burn up in normal operation for the moment
The part fails completely and there is a little hole (see picture) but I must say that
the part burn up after that I switch off the power supplies and then switch on in fact I design a board. On this board there is a micro controller so I restart from time to time the power supplies.
Yes some time i Have 5 Volts ( signal generator) on the inputs with no power supplies
The part is not hot when it burns up and I think that it burns up quickly
Are you able to share any information about your application, or possibly schematic? Typically, when I've seen this kind of failure it is due to very high transients being applied to the inputs, which exceed the 42V tolerance of the device. If the supply has excessive overshoot, that can also break down the part, eventually leading to catastrophic failure.
Any such information would be helpful!
The inputs is connected to a tektronix AFG3000 signal generator via a twist paire. it's outputs cannot exceed 10 Volts. The output part is connected to operational amplifier ( inverting ) via a 20K ohms resitor. The only explanation that I see is when I switch off switch on the rack power supplies there are some transients. however I placed two capacitors near the +/- pin power supplies. The power supplies is a linear power supply, I connected all the ground of the rack in the same point (Electromagnetic compatibility rules). I cannot give you a schematic for the moment because I am at home and I am in vacation for 3 weeks. I 'll send you the schematic and a picture of the rack when I 'll come back to work.
It might also be power supply sequencing. On some parts, it makes a difference whether the
plus supply or the minus supply comes up first. You could try it both ways and see if one is
worse than the other.
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