Driving MOSFET with IR2104

[Ankit Sahay]

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.

 

[Arouse1973]

What is your input voltage level?

 

[Ankit Sahay]

Input voltage is a PWM wave varying from some +5V to -5V

 

[Arouse1973]

The lowest input voltage is -0.3 volts not -5 volts.

 

[Ankit Sahay]

The lowest input voltage is -0.3 volts not -5 volts.

Yes, I just found out that. Thank you for pointing it out. I will try to implement the change and reply.

 

[Alec_t]

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]

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]

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]

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.

 

[Arouse1973]

You are welcome.
Adam