I've been assigned with debugging an existing 4-channel class-d amplifier based on IRS2093. Details and questions below. My idea was to put all questions in one post but if this is not desired then just let me know.  

Details for the current design: 
Class-D Driver: IRS2093MPbF
MOSFET: IRFB5615 (one pair per channel)
Topology: half-bridge
Fsw: 380 KHz
Dead-time: 105 ns. 
Vcc: 15V
Gate stoppers: 10 Ohm
Rail voltage: just under 100V (2 x 48,5V)

Junction temperature
One of the first things I noticed is that the IRS2093 runs quite hot, too hot for my taste. 
I did not do extensive testing but a quick test with opened case @ room temperature (much better cooling than worst case) gave me around 90 degrees celcius on the FLIR on the IRS2093. If I take into account the the unit will be running with the lid closed and the heatsink reaching > 70 degrees in worst case conditions then my best guess is that the IC is running too hot. 

I wanted to get a better picture of the power dissipation in our design, so I decided to check the math as described in Application Note AN-1146 - Junction Temperature Estimation. I got stuck on: 

7.4 PLSH: Power Dissipation of the High-side Level Shifter

PLSH = 0.4nC x fsw x VBUS x 4

All is clear except "nC". What is nC supposed to be?
I suspected the Mosfet Gate charge but that doesn't make sense as in the rest of the calculations, the gate charge is refered to as Qg. 

Anyway, in order to cool down the IC, my idea was to: 

- reduce Vcc from 15V to 12V. Sounds good?
- if that is not enough, reduce Fsw and/or rail voltage, find compromise between performance and reliability.  

The IRFB5615 have a gate charge of 27nc, seems like this should not pose a major issue for this IC?  

Feedback resistor. 
The Application Note AN-1146 shows a nice table for setting Fsw, assuming a feedback resistor of 47k. 

The design I'm working on seems to be loosely based on IRAUDAMP8 which uses Rfb = 100k. 
Not sure why the AN says to use 47k and IRAUDAMP8 uses 100k? There's not a lot of info to work with here so I guessed I'd better ask. 

Dead-time
DT is set to the highest value (105ns) which seems like quite a lot to me for IRFB5615 but I have yet to check double check if it can be reduced. My guess is that if it can be reduced, THD will drop but it won't solve the issue of the IRS2093 running so hot? 
I checked the THD and that seams to be OK (all things considering), the lowest being around 0,02% @ 50W. 

Output power
The amplifier was designed to do 4 x 200W @ 4 ohm or 4 x 300W @ 2 Ohm <= 1% THD, 1 KHz and in fact it does (at least for a short period).  My guess is that if we run 2 channels on 4 Ohm and two channels on 2 ohm, the 2 Ohm power rating will go up considerably, well exceeding 300W per channel which seems a bit much to me? Maybe pushing the limits of these devices? 

Over Current Protection
OCP is disabled in the current design and I would rather enable it if possible. However the Application note says: 

2. Switching Speed
Internal over current protection has a certain time window to measure the output current. If switching
transition takes too long, the internal OCP circuitry starts monitoring voltage across the MOSFET which
induces false triggering of OCP. Less than 20nC of gate charge per output is recommended.

The IRFB5615 have a gate charge of 27nc so we can't (or shouldn't) enable OCP? 
The word "recommended" leaves room for interpretation.  

Final note: Please note that this is not my design and that I'm quite new to class-d amplifier design. Just trying to learn and improve the existing design. So if you have any additional suggestions I'd be more than welcome to hear them. 

Hello! , I used arduino to try to set the value of Select Power Mode Profile setting, using I2c.write(0x20, 0x00, 0x01); Successful, but all the settings are restored after the power is cut off, can I not permanently write the configuration settings of the MA12070?

1.Both AD0 and AD1 are grounded

2.code

Clarification question: 
On the Datasheet for the MA12040P Amp IC, pins 49 and 64 are designated as do not connect, as they are internally connected to 5V -- however, on the MA12040P Amp Eval board (and documented on the eval board schematic) these pins are externally connected to 5V.

We've got jumpers on our board so we can connect to 5V or not -- 
Can you provide guidance here?  Why is the eval board connecting these pins to external 5V, despite the Datasheet guidance?

With respect to Infineon's Class D Audio Amp, P/N IRFB4020PBF, the datasheet states, "Can deliver up to 300W per channel into 8 (ohm) load in half-bridge configuration".

What is this 300 Watt limit based on?

What are the test conditions?

Assuming the thermal design is okay, can it allow for more power and current than limited by this statement?

Reference datasheet linked @ https://www.infineon.com/cms/en/product/power/mosfet/n-channel/irfb4020/

Greg