OPA1612: SoundPlus OPA1612 in replacement of OPA2134

Pierre CHAUSSE

Prodigy 20 points

Part Number: OPA1612
Other Parts Discussed in Thread: OPA2134, , OPA1678

Hi Community, TI!!!

I would like to upgrade an audio amplifier OPA2134 and the TI site web recommands me to change for a new OPA.

I found that OPA1612 was in the ultimate soundplus collection that's why i have change for it.

Unfortunatly with the new OPA1612 I have obtained a lot of noise on the output channel.

I try to use a cheap component like NE5532P, no noise, with OPA2134 no noise with the OPA1612 a lot of noise.

Do you know why i obtained this issue with the new OPA1612?

Thanks a lot

Pierre

over 6 years ago

0 kai klaas69 over 6 years ago

Guru 140200 points

Hi Pierre,

the OPA1612 has a very low input voltage noise but at the same time a very high input current noise. So, this chip will only produce low noise in combination with very low input and feedback resistances.

Kai

0 Pierre CHAUSSE over 6 years ago in reply to kai klaas69

Prodigy 20 points

Thanks a lot! Kai

0 Alexander Davis over 6 years ago in reply to Pierre CHAUSSE

TI__Expert 6250 points

Hi Pierre,
In addition to what kai said, if your application involves high impedances, where current noise will become a problem, you might want to consider a FET or CMOS input op amp such as OPA1678. While voltage noise will be somewhat higher than a bipolar input device, the lower current noise may yield an overall improvement in noise.

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OPA1612: SoundPlus OPA1612 in replacement of OPA2134