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Any idea how to remove ringing when PWMing? PWMing my laser diode in a low side driver configuration. Meaning my laser diode is connected to voltage+resistor in series and then the switch. (Done so I can avoid the almighty evil of a Pfet or the complexity of using a N channel mosfet as a high side driver). PWMing at about 700khz... could go higher but the ringing gets worse. Heres my scope output from my rigol DS1052SE.
CH1 = voltage across diode.
Second image:
CH1 is the gate of the mosfet. CH2 is the + terminal of the diode with respect to ground.
Any ideas? My source is a DC battery with an extra 20mF of capacitance added in parallel to help filter out any noise. Cabling is pretty short so it shouldn't be inductive kick back. Perhaps I should try a low side driver configuration? Ringing is less apparent at lower frequencies but i'm trying to build a high feq driver.
Basic schematic representation. To lazy to rewdraw... Pretend thats a nchannel mosfet and frequency source says 700khz...
CH1 = voltage across diode.
Second image:
CH1 is the gate of the mosfet. CH2 is the + terminal of the diode with respect to ground.
Any ideas? My source is a DC battery with an extra 20mF of capacitance added in parallel to help filter out any noise. Cabling is pretty short so it shouldn't be inductive kick back. Perhaps I should try a low side driver configuration? Ringing is less apparent at lower frequencies but i'm trying to build a high feq driver.
Basic schematic representation. To lazy to rewdraw... Pretend thats a nchannel mosfet and frequency source says 700khz...
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