DWM3640 CL1 value

[KriszXJR]

Board is ClassD 2000W with two irs21844. (DWM3640)
What is the correct value of CL1 / CL4.
I measure CL4 cca. 7,5uF, CL1 is shorted.
Thanks

 

[Perry Babin]

I've seen 4.7uF - 10uF used there on various boards. I don't think they're critical.

 

[KriszXJR]

Thanks Perry! I use 4,7uF.
This card is working perfectly. Amp is Hifonics BXi4000D.
I have another card, but it's faulty.
Replaced two 21844, 311, 072 it's working but output is lower than normal and crackle it's sound.
https://www.youtube.com/watch?v=XfU2VkVmw5g
I checked CL4, CL3, C11, and other side CL2, C4, CL1 and all resistors, and Q2-Q3-Q1-Q7 but everything is alright. Two 21844 is extreme heating.

 

[Perry Babin]

Is the 12v regulator for the 21844s very near 12v?

 

[KriszXJR]

Yes, it's 12V. (Rail +-100V and it's -88V.)

 

[Perry Babin]

Is the drive voltage low for both the high and low-side outputs of the ICs?

Don't let your probe slip if you're measuring at a point where pin spacing is tight.

 

[rrae]

Regarding CL1 / CL4 - what min. voltage it should be?

 

[Perry Babin]

The IC is rated for only 20v across the VB/VS terminals. 25v would be the minimum. I'd suggest using the highest voltage that will fit the pads.