My class D amp

[akraj]

Hi Aman,

Congrats, You are using AUD600 Rev1.0 and its fsw is @400KHz so you need 18uH,22uH or 33uH coil. 22uH is best for sound quality.



@Raj,

it is not 104(=100nF) caps use 100pF or 220pF/2Kv

Regards
MANOJ

Okay, I will use those caps to minimize resistor heat.

A good news, my t106 & t157-2 cores will be at my hand by Monday. It's from micro metal, I will start this project once again.

One thing, can I use micro to generate oscillating pulse instead of rc?

Thanks Manoj for your cordial support.

Thanks
Raj

 

[akraj]

Hi ALL

using T157-2 @40uH coil.Perfect for LF MID & HF crystal clear sound fsw @213KHz, No other noise

Regards
MANOJ

Hi Manoj:

I received T157-2 cores, would you please let me know how many turns for 1uH?

Should I use 40uH with aud600 v1?

Thanks
Raj

 

[Tekko]

Mini ring Core Calculator!

 

[manojtm]

I received T157-2 cores, would you please let me know how many turns for 1uH?

Should I use 40uH with aud600 v1?

Hi Raj,

i use T157-2 @40uH for fsw=@250KHz i like this freq.

(cal. is N^2*AL)
N=54Turns
AL=14
54*54*14=40uH

if you want to use this fsw(250KHz)and 40uH coil you need little changes at tlo71 ic circuit

Regards
MANOJ

 

[akraj]

Hi Raj,

i use T157-2 @40uH for fsw=@250KHz i like this freq.

(cal. is N^2*AL)
N=54Turns
AL=14
54*54*14=40uH

if you want to use this fsw(250KHz)and 40uH coil you need little changes at tlo71 ic circuit

Regards
MANOJ

Hi Manoj:

Higher freq = better sound, right?

250KHz is good for all range or for sub only? If I want to use this in your v1 design what change I need to do?

Thanks
Raj

 

[Tekko]

250kHz for lowfi, 400kHz for midfi and 800kHz for hifi.

 

[akraj]

250kHz for lowfi, 400kHz for midfi and 800kHz for hifi.

800kHZ? IR designed their iraudamp9 with Self-oscillating – 300kHz.

is that not good?

 

[manojtm]

250kHz for lowfi, 400kHz for midfi and 800kHz for hifi.

Hi tekko,

this is not true.10 times higher than audio band is better for any good designed class d amp
so 200Khz is enough for all band. and 300KHz is max.(today's components for higher output)otherwise efficiency will be dropped.

Regards
MANOJ

 

[Tekko]

Try saying that to the ppl that have made up their minds that class d cannot be used for anything but subwoofers.

I can agree that 200-250kHz is enough for a class d to sound good, it just feels wrong.

 

[akraj]

Hi tekko,

this is not true.10 times higher than audio band is better for any good designed class d amp
so 200Khz is enough for all band. and 300KHz is max.(today's components for higher output)otherwise efficiency will be dropped.

Regards
MANOJ

Hi Manoj:
What is the relation between fsw, lc? I mean if the fewq is x what will be uH and cap value with inductor?

Thanks
Raj

 

[manojtm]

Hi Manoj:
What is the relation between fsw, lc? I mean if the fewq is x what will be uH and cap value with inductor?

Hi Raj,

i don't understand what you ask for?

2nd order LC filter you are calculated only for cut off freq. only ; but in sigma-delta filter coil is also one of the part related to the fsw.

so fsw=300KHz to 400KHz use 18/22/33uH coil depends your speaker impedance

Regards
MANOJ

 

[aman khalsa]

RM 10 on aud600.

hello sir i m using RM10 on ur amp.. amp is working good.but on 110vc dc( testing ) fets geting hot .. using 23uh . i m not using 7806 i m using 7805 . is that any problem ??

 

[norazmi]

+- 110vdc?

 

[aman khalsa]

yes sir + -110v dc

 

[akraj]

hello sir i m using RM10 on ur amp.. amp is working good.but on 110vc dc( testing ) fets geting hot .. using 23uh . i m not using 7806 i m using 7805 . is that any problem ??

Heat might be okay, but how much?

 

[akraj]

Hi Raj,

i don't understand what you ask for?

2nd order LC filter you are calculated only for cut off freq. only ; but in sigma-delta filter coil is also one of the part related to the fsw.

so fsw=300KHz to 400KHz use 18/22/33uH coil depends your speaker impedance

Regards
MANOJ

Hi Manoj, you got it right. I wanted to know at what fsw what will be the L value, C value & Spk impedance.

Is the any chat of this? Or equation?

 

[manojtm]

Hi Raj,

just you take 6R speaker load and calculate cut-off freq. IRSOUND will help you to calculate this

Regards
MANOJ

 

[stewin]

hello sir i m using RM10 on ur amp.. amp is working good.but on 110vc dc( testing ) fets geting hot .. using 23uh . i m not using 7806 i m using 7805 . is that any problem ??

which fets are you using as outputs?

 

[aman khalsa]

I m using IRFP250...

 

[manojtm]

Hi AMAN,

IRFP250N can handle up to +/-122V supply and do not connect 2R & 4R load. only for 8R load.

Regards
MANOJ