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Driving MOSFET with IR2104

Ankit Sahay

Apr 1, 2016
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Apr 1, 2016
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I am designing a Class D audio amplifier and using IR2104 to drive the two N-Channel MOSFETs IRF3205.
I have enclosed my circuit in the attachement. The output at Ho and Lo pin is not high enough to drive the gate of the mosfets. The value at these Ho and Lo pins are in mV. Any suggestion for the circuit?
I have to design the circuit for audio input but as of now I am using a 1kHz sine wave as audio input and 5KHz triangular wave to create 5KHz PWM wave which I am giving input to 'IN' pin of IR2104.
 

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Arouse1973

Adam
Dec 18, 2013
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The lowest input voltage is -0.3 volts not -5 volts.
 

Alec_t

Jul 7, 2015
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Sounds like the SD pin isn't at logic high, the chip suffered from having -5V on its input, or else the bootstrap isn't working. Have you tried adding a load to the output?
 

Ankit Sahay

Apr 1, 2016
5
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Apr 1, 2016
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SD is actually SD' so it is logic high only. I have some doubts in bootstrap as well. Yes, i did connect a speaker. but no proper output from Lo and Ho
 

Arouse1973

Adam
Dec 18, 2013
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Reduce the nagative voltage to its min and if this does not work then make voltage measurment of each pin with respect to common and post them here.
Adam
 

Ankit Sahay

Apr 1, 2016
5
Joined
Apr 1, 2016
Messages
5
Reduce the nagative voltage to its min and if this does not work then make voltage measurment of each pin with respect to common and post them here.
Adam
Yes, I will do for sure. Weekends have arrived so I cant go to Lab for couple of days. I will take these notes and implement them on Monday and will report here accordingly. Till then, a very big thank you to all of you.
 
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