OPA2333: Keeps shorting out

Nicolai Weis

Part Number: OPA2333
Other Parts Discussed in Thread: OPA333, OPA188

Hello.

Im making a temperature measuring project. We are using an OPA2333 and it keeps shorting out. We have shorted 2 now. They both work for about 30min and then the power supply goes into current limiter.

This is our circuit where the PT100 is set to the maximum resistance we want. Vss = +5v. Vcc = -5v.

The biggest annoyance is no one here can see why its shorting out (nothing seems wrong with out pcb). So i thought maybe some of you could explain why?

We have one OPA2333 left, and would like to solve this problem before we try it.

over 6 years ago

0 Thomas Kuehl over 6 years ago

TI__Guru* 93105 points

Hi Nicolai,

You stated that you are using Vss = +5v. Vcc = -5v, which is a total of 10 V across the OPA333. The absolute maximum supply rating for the OPA333 is 7 V (+/-3.5), but is should be used with less. Therefore, the OPA333 is being subjected to too high of voltage and is breaking down.

If you need a higher supply voltage chopper op amp, take a look at the OPA188:

www.ti.com/.../opa188.pdf

Regards, Thomas

Precision Amplifiers Applications Engineering

0 Nicolai Weis over 6 years ago in reply to Thomas Kuehl

Prodigy 40 points

Oh my god how did i miss this. Thank you so much.
We dont have time to order more components, but we already have a OPA333 laying around so we are gonna split 5v into +/- 2.5v with it and hope for the best

0 Thomas Kuehl over 6 years ago in reply to Nicolai Weis

TI__Guru* 93105 points

Hello Nicolai,

The OPA2333 should be completely reliable with +/-2.5 V supplies. I am glad I could help.

Regards, Thomas

Precision Amplifiers Applications Engineering

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OPA2333: Keeps shorting out