LM4911Q-Q1: LM4911Q-Q1 Compatible with TLV320AIC3109-Q1

Danilo A.

Part Number: LM4911Q-Q1
Other Parts Discussed in Thread: TLV320AIC3109-Q1

Hi Team,

The TLV320AIC3109-Q1 has low output power of 15mW when connected to a 32-ohm headphone. The customer would like to increase the output by connecting to LM4911Q-Q1. Are these two devices compatible? What are the passive components that needs to be added between the output of TLV320AIC3109-Q1 and input of LM4911Q-Q1? The application is mono.

Regards,

Danilo

over 5 years ago

0 Luis Fernando Rodriguez S. over 5 years ago

TI__Guru* 84915 points

Hi, Danilo,

Yes, usually all our audio codecs/DACs with headphone output are compatible with our analog amplifiers. The LM4911Q-Q1 maximum input level is actually above the output level that the TLV320AIC3109-Q1 can deliver. So, there's no risk to damage the device.

I just recommend to connect a passive filter to remove the out-of-band noise. All our audio converters with integrated delta-sigma converter contain a high-frequency noise. In order to avoid its amplification with an external component, a low-pass RC filter should be connected between both devices. Please take a look at the document below for details:

http://www.ti.com/lit/an/slaa313/slaa313.pdf

I hope this helps you. Please let me know if you have additional questions or comments.

Best regards,
Luis Fernando Rodríguez S.

0 Danilo A. over 5 years ago in reply to Luis Fernando Rodriguez S.

TI__Mastermind 29540 points

Hi Luis,

Thank you for this info and suggestions. The customer wants to know the difference in sound pressure level (dB) between 30mW & 55mW when driving a 16-ohm headset.

Regards,

Danilo

0 Luis Fernando Rodriguez S. over 5 years ago in reply to Danilo A.

TI__Guru* 84915 points

Hi, Danilo,

Please take a look at this note for details about the sound pressure level:

https://e2e.ti.com/blogs_/archives/b/precisionhub/archive/2015/12/21/amp-up-your-cans-how-much-power-do-your-headphones-need-part-1

Best regards,
Luis Fernando Rodríguez S.

0 Danilo A. over 5 years ago in reply to Luis Fernando Rodriguez S.

TI__Mastermind 29540 points

Hi Luis,

Thank you for sharing this very informative blog.

Regards,

Danilo

0 Danilo A. over 5 years ago in reply to Danilo A.

TI__Mastermind 29540 points

Hi Luis,

The TLV320AIC3109-Q1 is a mono CODEC while the LM4911Q-Q1 is a stereo amplifier. Based on Figure 2 from the datasheet of LM4911Q-Q1, can we just connect Input 1 or 2 to ground to disable one of the amplifiers?

Regards,

Danilo

0 Luis Fernando Rodriguez S. over 5 years ago in reply to Danilo A.

TI__Guru* 84915 points

Hi, Danilo,

Yes, it is possible to use only one input as you correctly mentioned. The other input can be AC-coupled to GND. The active input can be just connected to the TLV320AIC3109-Q1 output through the out-of-band filter that I mentioned in my first response.

Please let me know if you have additional questions or comments.

Best regards,
Luis Fernando Rodríguez S.

Audio

Audio forum

LM4911Q-Q1: LM4911Q-Q1 Compatible with TLV320AIC3109-Q1