[SAMA5D2] driving headphones and speaker

Discussion around products based on ARM Cortex-A5 core.

Moderator: nferre

User avatar
andyp
Posts: 8
Joined: Thu Oct 09, 2014 12:19 pm

[SAMA5D2] driving headphones and speaker

Mon May 20, 2019 3:34 pm

I'm looking for a bit of guidance on using the audio features of the SAMA5D2x devices. I need to be able to drive a mono speaker or stereo headphone. In typical fashion, if the headphones are plugged in the speaker should be turned off.

I can see there are potentially three options from a hardware perspective:
  • Use an I2S CODEC that has both speaker and headphone outputs at the appropriate power and impedance
  • Use the SAMA5D2x on-device class D amplifier for the speaker and an external I2S device for the headphones
  • Try to drive both from the on-device class D amplifier and modify impedance at an analogue level
Any recommendations on the best way to go?

-Andy.
blue_z
Location: USA
Posts: 1978
Joined: Thu Apr 19, 2007 10:15 pm

Re: [SAMA5D2] driving headphones and speaker

Tue May 21, 2019 11:25 pm

andyp wrote: I'm looking for a bit of guidance on using the audio features of the SAMA5D2x devices.
Did you read the app note "Getting Started with the SAMA5D2 Audio Subsystem"?

andyp wrote: Any recommendations on the best way to go?
What are your criteria for "best"?

FYI the integrated Class D amplifier has a "digital" output and lacks an analog power stage. IOW the SoC will not drive a speaker or headphones load.

Regards
User avatar
andyp
Posts: 8
Joined: Thu Oct 09, 2014 12:19 pm

Re: [SAMA5D2] driving headphones and speaker

Sun May 26, 2019 11:33 am

In this case "best" means the minimal amount of re-inventing the wheel so readily available reference schematics to work from and pre-existing Linux driver support.

I'm thinking WM8731 CODEC on the I2S interface which should drive the headphones directly and a simple audio amplifier (LM4889 possibly) for the speaker.

-Andy.

Return to “SAMA5D Cortex-A5 MPU”

Who is online

Users browsing this forum: No registered users and 3 guests