AD620 Mivrovolt amplifier

Hi i have a question. Recently i bought a amplifier that can amplify milivolt and i dont know wether the amplifier can amplified voltage or not . Can someone help me

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Study the data sheet or user manual, and post a link to the product page.

This is certainly possible. A microphone preamp amplifier typically has a gain of 100-1000 which boosts the few-millivolt microphone signal to audio line level (about 1V).

It's not hard to get gain of 1000 from an op-amp.

But it can be tricky because any electrical noise also gets amplified, and there is always some noise generated by the electronics and noise can get-in through the power supply.

Most op-amp circuits use dual (plus & minus) power supplies. That allows you to amplify AC (required for audio) and/or it allows the output to go all the way to zero.

The Arduino's analog-to-digital converter can't handle negative voltages so audio has be biased.

But high gains in a single-stage will lead to reduced bandwidth (not usually a huge problem for audio bandwidth if the opamp has 10MHz GBW or more, but it will bite you if you use a low performance opamp like an LM358 for instance).

Good design usually limits single-stage gain in an opamp circuit to x30 or so in order not to throw too much bandwidth away.

The photo shows the middle chip to be an AD520A which is interesting as that instrumentation amp is supposed to be obsolete. Its likely a fake chip. Anyway the AD520 supports gains from 1 to 1000, but its bandwidth is limited to 25kHz at g=1000.

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