Wheel Potentiometer to Digital Potentiometer Volume Control

Thread Starter

skimzor

Joined May 17, 2023
7
Hi All,

I'm working on a handheld gaming console project and need some assistance with converting a wheel potentiometer to a digital potentiometer to control volume:

Current audio circuit:

  1. The CPU outputs a 65kHz PWM audio signal
  2. I am planning on using an LM4853 IC as the amplifier
  3. The console uses a mono 8Ω 1W speaker and is able to output to stereo when headphones are inserted
  4. Currently using a 10k dual wheel potentiometer to control the volume
  5. I have access to a 5V rail and a dedicated 3.3V rail to power the amplifier IC

1708397917589.png

Instead of the the wheel potentiometer, I would like to control volume with push buttons. I found the MAX5456/5457 IC that looks like it would fit my needs (dual 10K pot, log, able to use momentary SPST switches to control volume, etc.). I'm having a hard time wrapping my head around how the volume control works. I've put together this circuit but I'm not entirely sure if it works (i.e. when VOLUP button is pressed, the wiper moves towards the H terminal and that increases volume?):

1708398085883.png

Anyone mind checking my work and providing feedback? Will the MAX5457 replicate what the 10Kx2 wheel potentiometer does? I don't need balance control mode or a mute button function. Also, I'm not entirely sure what the difference between VDD and VLogic are so an explanation of that would be appreciated as well. Thank you!
 

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