Sound output

  • Is there a reference hardware design of how to connect some little speakers (e.g. 1W) to the PicoMOD7A (amplifier, resistors, capacitators, speaker)?


    The cause of my question is that we have much noise on the speaker. We're using an audio amplifier and a little speaker. We can hear all the sound we're playing on the PicoMOD correctly. But we also hear much noise. This noise seems to depend on memory access. If I don't do anything on the memory bus the noise is very silent. If there's much traffic on the memory bus (also during the complete boot process) the noise can be very loud - it's as loud as playing a soundfile.


    Thanks for any idea.

  • We don't have noise on line-out.
    What are your mixer settings?
    Best practice is to set the mixers in the codec to maximum level and adjust the amplifier to the desired volume.
    Also the sound files should have a sufficient level.
    This gives best results.

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • We only have line-out, no amplifier.
    In other projects we used LM4880 and LM4861 as amplifiers.
    Do not power the amplifiers with the 3.3V used for the PicoMOD, else you will have noise.
    It is crucial to have a clean power supply and to route the analog signals away from all other signals and power supplies.

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.