Hello everyone , i hope you all having a great day!
Ive been working on a audio project and i want to use a bluetooth module for that. I have the schematic posted here to have a better view. So RL is the bluetooth module ground, im using a low side switch with 2 mosfets. The problem is im getting a "bzzzz" kind of noise when using the bluetooth module and im not really sure why this is happening and what is causing this. I do have decoupling capacitors. (The second Mosfet also has a 22k resistor and capacitor in the gate but its not visible in the picture below)
Ive been working on a audio project and i want to use a bluetooth module for that. I have the schematic posted here to have a better view. So RL is the bluetooth module ground, im using a low side switch with 2 mosfets. The problem is im getting a "bzzzz" kind of noise when using the bluetooth module and im not really sure why this is happening and what is causing this. I do have decoupling capacitors. (The second Mosfet also has a 22k resistor and capacitor in the gate but its not visible in the picture below)
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The IRF640 requires 10V gate drive, not 5V. Try a logic-level MOSFET, rated at more like 20--40V and a lower on-resistance than 180milliohms.
If you have any other DC-coupled signals into the bluetooth unit it may be a mistake to use low-side switching.
If you have any other DC-coupled signals into the bluetooth unit it may be a mistake to use low-side switching.