OPA1622: EMI rejection vs the TPA6120A2

Viktorija Cecil

Part Number: OPA1622
Other Parts Discussed in Thread: TPA6120A2,

My customer is asking:

As an alternative, I noticed a lot of people are using the OPA1622 for a headphone amp. Any thoughts on its EMI rejection vs the TPA6120A2?

Let me know

Thanks

Viktorija

over 8 years ago

0 John Caldwell over 8 years ago

TI__Genius 12345 points

Hi Viktorija,
Since both the OPA1622 and TPA6120A2 use bipolar junction transistors (BJTs) in the input circuitry of the amplifier, both of them are pretty sensitive to EMI. We do not have measured EMI-RR on the OPA1622 at this time, but I can tell you from experience working with it, it will pickup EMI signals if there are long PCB traces or wires to the input. Customers have had success suppressing EMI using an RC lowpass filter placed directly at the OPA1622 inputs (inside the amplifier feedback loop). 100 Ohms + 15pF is an effective combination.