LM4930: Audio codec to drive a H250 handset

Sankar,

The LM4930 was designed for mobile phones at a time before the modern smart phone. There is a bidirectional PCM interface for audio. this interface is limited to 16bit/8kHz sampling while the I2S input can support higher sampling rates (for listening to music for example)

If you want a codec with I2S In/Out you could really choose just about any other TI Codec. the LM49352 is a similar device to this but with I2S in/out , ground centered headphone outputs, a higher power speaker amplifier, more digital processing options, and higher SNR.

I'm not really familiar with the H250 Handset, perhaps you can provide some specs? impedance of the speaker? mic? etc..

best regards,
-Steve Wilson

Sankar,

So in order to get 25mW with a 1k impedance you're going to need greater voltage potential. These LM devices are all below 5V and if you want to hit the 25mW mark you'd need a 7V peak output.
the LM49352 will give you more like 2mW at 1k. it is intended for lower impedance headphones.

best regards,
-Steve Wilson

Hi Sankar,

Suitable for what exactly? You want to hit 25mW at 1k?

www.ti.com/.../TPA6120A2

This is a headphone amplifier that can use rails up to +-15V. obviously you wouldn't need supplies that high. alternately you could use simple opamps, especially if you don't need such high performance.

-Steve Wilson