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enter image description hereI am having a problem with some of the class d amps I've played with (PAM8302A), and it seems like this article here describes my problem: https://www.edn.com/design/analog/4313726/Add-headphones-to-a-Class-D-amplifier essentially the audio circuit turns off because of the headphone plug sharing a common ground or something. I am making a pi zero pwm to analog amplifier circuit and some suggestions would be appreciated.PAM8302A

Edit: How is this? 220uF cap highlighted

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    \$\begingroup\$ There is a short circuit through C3. I can see a net / trace going through it. Don't base your PCB design on this. \$\endgroup\$ – Transistor Mar 22 at 23:40
  • \$\begingroup\$ I just did that to mock up a capacitor in that location, I just now redid the two traces in and out of the capacitor. \$\endgroup\$ – Vincent Pipitone Mar 23 at 0:21
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Insert a 470uF capacitor into the VO_P output with the capacitor + lead going to the IC. Now you are no longer shorting out the DC bias voltage at the output pins. Use small cell-phone type headphones or earbuds to get enough volume. You need 2 of these ICs for stereo sound. This IC cannot drive studio grade headphones, at least not to any useful volume.

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  • \$\begingroup\$ Do you suppose I could add 4 x 100 uF caps and 1 x 70uF all in parallel? I have some major clearance issues and 470uF is the limit of surface mounted ceramic capacitors, with the max voltage that I found of 4V and 10$ a pop. \$\endgroup\$ – Vincent Pipitone Mar 22 at 3:17
  • \$\begingroup\$ That is tough because that value is normally aluminum can type electrolytics. You can vertically stack SMD capacitors to get a higher value. Also small headphones and earbuds tend to be 32 ohms, so you get bass with less capacitance. I would stack the highest SMD value possible. Even 200uF should be ok. \$\endgroup\$ – Sparky256 Mar 22 at 3:47
  • \$\begingroup\$ Please check out the edit I made above. \$\endgroup\$ – Vincent Pipitone Mar 22 at 23:23
  • \$\begingroup\$ That is correct and should work fine. Remember you cannot use VO_N of either channel. \$\endgroup\$ – Sparky256 Mar 23 at 0:00

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