Idle Channel Noise [TPA3110D2]

Hi, MJ,

How does your noise level compare to the 65 uV quoted in the d/s?

-d2

Hi d2,

I couldn't measure the exact noise level in uV as my DSO doesn't support that tiny measurements.

But the hiss is noticeable as soon as i enable the TPA3110D2, when i disable it, the hiss is gone.

Its very tiny and heard only when i hear it on the headphones in a very silent room.

Is this behaviour normal ?

Thanks,

- Mj

MJ,

Headphones? The TPA3110D2 is a 15W class-D amp!

How do you have it configured to drive HP? It requires BTL operation, the modulation technique we use in this IC is not compatible with single-ended use.

-d2

The headphone is one used for diagnostics of hearing impaired.

The speakers inside the headphone are 8Ohm, 2W rating.

Would TPA3110D2 be an overkill ?

I can see that the power rating of the amp is higher than that of the headphone speakers.

I am a novice at audio applications. Please guide.

Thanks.

Hi, MJ,

Are the speakers connected in BTL (bridge-tied load) or SE (single-ended)?

Here is a link to a Design Note that explains BTL.

Do you have some kind of specification that you have to meet?

-d2

The speakers are connected in BTL.

The specification i have to meet is that the output sound level should vary between 0dB to 120dB

at frequencies between 125Hz to 16KHz

MJ,

Do you know the sensitivity of your speakers?

-d2

No. I don't know the sensitivity of the speakers.

But the max voltage (measured after the LC filter) goes upto 2V (peak-to-peak) for 90dB output.