SGTL5000 connection

[carlosvernich]

We are using a SGTL5000 to play-back audio (using line-out) and capture audio (using mic-input), with an iMX51.

If the LINE_IN signals of the SGTL5000 are not used, what is the recommended connection for them? (leave unconnected, tie to GND, tie to GND via a capacitor or resistor...)

The typical application schematic on the datasheet does not clarify what to do with these pins if not used.

Thanks for your help!

[nikolaydimitro1]

Hi Carlos,

Connect the unused Line-In inputs to GND. This is the most effective way to prevent hum/audio noise/RF noise from coupling into the analog circuit. Also, by happy coincidence this is the cheapest way.

The only "gotcha" - if this is a battery-powered device, just double-check that the codec's idle current is not increased significantly by this connection.

Regards.

[alejandrolozan1]

Thanks Nikolay,

That helps me a lot!

/Alejandro