Author Topic: Op amp supply drawing large current.  (Read 601 times)

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Offline Joe_echoTopic starter

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Op amp supply drawing large current.
« on: October 03, 2023, 05:53:05 pm »
I have some tl074cn chips that I'm experimenting with and trying to refresh my memory on their operation.

I have them hooked up to a single supply rail with 12v and ground which I believe should work, however the supply is drawing a large amount of current almost like a short circuit.

Am I being a muppet and missing something vital?
 

Offline Manul

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Re: Op amp supply drawing large current.
« Reply #1 on: October 03, 2023, 06:55:07 pm »
Obviously something is very wrong. Have you double checked the pinout? Can you post schematic?
 

Offline Joe_echoTopic starter

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Re: Op amp supply drawing large current.
« Reply #2 on: October 03, 2023, 07:19:13 pm »
I have checked the pinout several times just to make sure its not me.

Here is the schematic

 

Offline Manul

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Re: Op amp supply drawing large current.
« Reply #3 on: October 03, 2023, 07:29:58 pm »
the supply is drawing a large amount of current almost like a short circuit.

Generally it would be better if you would give numbers, no epithets, but I assume you mean really high current like 1A or 3A. In that case I can only suggest to double check pinout again and try another (new) IC. Current one might be already irreversibly damaged.
 

Online Kim Christensen

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Re: Op amp supply drawing large current.
« Reply #4 on: October 03, 2023, 07:35:05 pm »
I have checked the pinout several times just to make sure its not me.
Here is the schematic

But what is the pinout? Your schematic doesn't show it.
It should be something like this:
 

Offline magic

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Re: Op amp supply drawing large current.
« Reply #5 on: October 03, 2023, 07:37:45 pm »
The schematic is sensible.

If the circuit draws more than a few mA, something is clearly not the way you think.
Wrong pinout.
Damaged chip.
Wrong part (maybe fake chip?).
Reversed PSU.
Bad PSU ammeter.
...
 

Offline Joe_echoTopic starter

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Re: Op amp supply drawing large current.
« Reply #6 on: October 03, 2023, 07:40:16 pm »
Sorry, yes the pinout of my device matches. Vcc= pin 4, Vee= pin 11.

I believe they maybe fake ICs.
 

Offline Joe_echoTopic starter

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Re: Op amp supply drawing large current.
« Reply #7 on: October 03, 2023, 07:40:56 pm »
Yes, 2amp was drawn before my OCP kicked in.
 

Offline magic

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Re: Op amp supply drawing large current.
« Reply #8 on: October 03, 2023, 07:43:54 pm »
Any pictures of the chips and/or the exact test setup?
 


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