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Comments on Is this AD8307 fake?

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Is this AD8307 fake?

+1
−5

I am trying to test a AD8307. Here are my connections:

AD8307

(pins not shown are left unconnected, and also pin 8).

I get a quiescent output voltage at pin 4 of about 850 mV with respect to ground, which, to my best understanding, means that the IC is fake.

What do you think?

ADDED: As I wrote, pin 8 is left unconnected. According to the datasheet, the input impedance of the IC is 1 kOhm. I am not working inside a microwave oven or near high voltage sparks, so, I can hardly imagine that the tiny pin 8 acts as an antenna or so to provide such a voltage discrepancy, but to make that sure, I tried to put it in a metal box and that made no difference.

IC amplifier
posted over 3 years ago
3y ago
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coquelicot‭
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1 comment thread

General comments (7 comments)
General comments
Lundin‭ wrote over 3 years ago
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What makes you think it is fake in the first place? Did you buy it from the spot market?

JRN‭ wrote over 3 years ago
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Do you have a "real" AD8307? What is its output at pin 4 for this circuit?

coquelicot‭ wrote over 3 years ago
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@Lundin. I don't know what is "spot market", but if that means "Chinese market", then yes. That question is also a way to know if I am understanding right the IC.

coquelicot‭ wrote over 3 years ago
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@Joel Reyes Noche. Yes, I have a real AD8307, and I tried two from the five I've ordered. According to the datasheet (link in the question), output 4 is the "out" pin.

Lundin‭ wrote over 3 years ago
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@coquelicot‭ It means buying from component traders instead of the usual well-known vendors. There is a huge market of people buying and selling electronic components similar to stock trading. It's the last resort where you go when you can't buy obsolete parts from a trusted source. And it is filled with scammers, cheap illegal copies, silicon dummies and so on.

JRN‭ wrote over 3 years ago · edited over 3 years ago
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What I mean is, if the chip you suspect is fake outputs a "quiescent output voltage at pin 4 of about 850 mV," then what is output by a real AD8307? (Not just in theory, but in practice.)

coquelicot‭ wrote over 3 years ago · edited over 3 years ago
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@Joel Reyes Noche. An excellent question! I would have give you a +1 if I could :-)