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MP3 player project

kalio

Hi guys

 

Recently i got a bu94605kv-e IC from Rohm and i decide to make my own mp3 player based on that IC.

This is my firs project in this wounderful embedded world so i don't know if all i made is ok.

Here is the Eagle schema:

 

http://i51.tinypic.com/1pwcc1.jpg

 

Here is an archive whit datasheet for IC and a file whit functional specification from a IC within that series:http://www.mediafire.com/?xxrwm2l2jt9xdre/?xxrwm2l2jt9xdre

 

Questions:

     Can I use a single pull-up resistor for more than one connection?

     I'm not sure if I chose corectly the bypass caoacutir(C6 10uF).

     I don't know what to do whit 54 pin(VCDACO);in the datasheet they say 'Audio DAC reference voltage output'?

     I will need to use a IC for audio signal aplification?

 

Sorry for my english...

 

Thank's image

  • Hello Kalio,

     

    You are way out of your depth here ! I don't have time to design a circuit for you but here are a few quick observations to stop you blowing up too many chips !

    1) The BUK94605 needs a 3.3V DC supply - your 9V battery will kill it stone dead.

    2) You should allow a small ceramic decoupling capacitor (100nF in 0603 or smaller package) from each VDD (+ve supply) pin to ground.

    3) Your board will need a ground plane.

    4) I can't tell from the 2 page ROHM data sheet if it will drive headphones directly - do you have more detailed  application notes ?

  • in reply to michaelkellett

    i'm aware of the 9V battery;i will change it...

    here is an archive whit datasheet and a functional specification for BUK94603 which is about the same

     

    Thx

  • in reply to kalio

    Hello Kalio,

     

    Not much of  data sheet even when you get the big one  - a connection diagram would have helped. I'm sorry I can't go through all of it but it looks as if you will need an audio amplifier chip to drive headphones because the ROHM chip outputs are described as line level.

    Make sure that your 3.3V supply can manage enough current for the amplifier, SDIO card and mp3 chip all at once.

  • in reply to michaelkellett

    Audio outputs are (based on data sheet) line outputs, max level 0.67V rms, so headphone amp is needed.

     

    'Audio DAC reference voltage output' - reference or supply voltage of internal audio DAC, perhaps bypass capacitor is needed.