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Class D Audio Amplifier IC Forum Discussions

yogeshks1
Level 1
Level 1
First reply posted 5 sign-ins First question asked

Dear All members

we are making the 1000+1000w , 2 CHANNEL CLASS S AMplifier to run speckaer of 4ohm load. This is running ok,,,we are stuck one point

1) In case Mosfet ar short the DC voltage will reach to speakers and this can blow the speakers.

How to protect this situation.

In the Power supply line to amplifier (+ / - 70VDC) we have fuse .....can we have better solution to protect the speaker from having DC voltage in case Mosfet are Short

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Kieran_Pan
Moderator
Moderator
Moderator
50 sign-ins 10 solutions authored First like received

Hello Yogesh,

I have double checked the function description (application notes) of IR2092S.
It already has the OCP function and you just need to follow the steps and calculate the value of the resistors.
It won't damage the IC. By the way, you have already added the fuse which add another protection in the circuit.

Best regards,
Kieran 

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Kieran_Pan
Moderator
Moderator
Moderator
50 sign-ins 10 solutions authored First like received

Hello yogeshks1,

1. You should know that IRS2092SPBF is the driver for 500W application. However, your design is 1000W+1000W. Overpower may cause the problem.

2. A DC blocking capacitor C3 should be connected in series with RIN to minimize DC offset in the output. You could try to change the block capacitor of the input to protect the circuit.

Best regards,
Kieran

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yogeshks1
Level 1
Level 1
First reply posted 5 sign-ins First question asked

Thanks Kieran

Can u pl share document reference ..where i can check the  location of C3 and RIN.?

we are using bridge mode to take 1000w 

rgds

yogesh singhal

 

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Kieran_Pan
Moderator
Moderator
Moderator
50 sign-ins 10 solutions authored First like received

Hello Yogesh,

1. The Link of  product is:
https://www.infineon.com/cms/en/product/power/class-d-audio-amplifier-ic/discrete-class-d-audio-ampl... 

2. Download the function description of it

3. See Figure 2

4. You could know more about from the link of 1

Kieran_Pan_0-1670320871611.png

Kieran_Pan_1-1670320917668.png

 

Best regards,
Kieran

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yogeshks1
Level 1
Level 1
First reply posted 5 sign-ins First question asked

Thanks Kieran

We are having C3 in our circuit.

the concern is: If output mosfet is short, than DC supply voltage will come via RFB resistor to Input Pin of IR2092S..and this voltage can damage the device.

how to protect the device in this situation..when mosfet is short... ..

i hope i am able to define the problem 

 

rgds

yogesh singhal

 

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Kieran_Pan
Moderator
Moderator
Moderator
50 sign-ins 10 solutions authored First like received

Hello Yogesh,

1. The key point is that you should prevent the short circuit, so you need to set the right dead-time of two MOSFETS.

2. You may add TVS diode at the output of the circuit parallel with the speaker.

Best regards,
Kieran

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Kieran_Pan
Moderator
Moderator
Moderator
50 sign-ins 10 solutions authored First like received

Hello Yogesh,

I have double checked the function description (application notes) of IR2092S.
It already has the OCP function and you just need to follow the steps and calculate the value of the resistors.
It won't damage the IC. By the way, you have already added the fuse which add another protection in the circuit.

Best regards,
Kieran 

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