TAS6422 2.1MHz Class-D Digital Amp Project

[chchyong89]

with 2.1Mhz i believe you need some litz wire winding inductors to minimize skin effects on the coppers.

 

[CyberPit]

Inductors are invistigated

Hi chchyong89-San,
Good point!

High frequency switching circuit requires good quality parts. This reconstruction filter is not in a feedback loop, so it might not be a important, but I had interested on my using inductors.
This ver.3 board picture uses #2 inductors.

My board has 2 various inductors for reconstruction filter.

#1. Sagami-Elec 7G14C-4R7N-R (4.7uH, DCR=4.9mOhms, 20A max.)
#2. TT Electronics HA72L-12654R7LFTR(4.7uH, DCR=11.2mOhms, 13.5A max.)


And I attached one very bad example which mounted on HX-M190
#3. burning-hot toroidal inductor removed form XH-M190 board.


According to the measured result #1 and #2 inductors are keeping inductive over 10MHz or more. So I think those are good enough for my 2.1MHz PWM amplifier.

In other hand, #3 inductor is terrible quality part. As a result of this, XH-M190 has a burning-hot reconstruction filters.

 

[drMordor]

In other hand, #3 inductor is terrible quality part.
White-yellow rings - max 100kHz

 

[CyberPit]

Model Name Wrong XH-M190 --> HX-M139

Sorry!!
I made mistake Model name of Burning-Hot #3 inductor was removed from XH-M139. (Not XH-M190)


A picture of "Burning-Hot" XH-M139（On the way of modification Snapshot)