MHz class d amp

[fumac]

my smd ucd🙂 stero,up to1.2MHz pwm

i 'm from china, english not well🙂

i have dev the smd ucd pcb, and drive the freq up to 1.2MHz
it can output a more sweet sine osc in 20K.


picture here:
http://www.class-d.net/UploadFiles/200718172817117.jpg

i'm thinking how to fix it to BTL, some body help🙂

tks🙂

An externally hosted image should be here but it was not working when we last tested it.

 

[Baldin]

Hi fumac

Sounds very interesting, but I can't seem to access the file!
Is the design based on the Philips App note?
How much power can it deliver?

 

[fumac]

here the link

An externally hosted image should be here but it was not working when we last tested it.

http://www.class-d.net/UploadFiles/20071920500833.jpg

Baldin:

Sounds very interesting, but I can't seem to access the file!
Is the design based on the Philips App note?
How much power can it deliver
------------------
some diffrent with Philips App note,
base on it ,but we change something
we r trying to upgrade the power to 300~350WRMS

 

[RX5]

fumac,



whats the relay for?

and you say your "heatsinking" thosew SMT mosfets??? wow 😀

 

[fumac]

hi RX5
the relay for protec the speaker

2 way to heatsinking the fet
1.the pcb,
2. the Aluminum

 

[RX5]

fumac,

can you give info/link/datasheet for output mosfet/s used....

 

[fumac]

most mosfet can work on 1MHz

most mosfet can work on 1MHz perfect
u can read the datasheet, most of them were tested on 1Mhz
the correct type that i'm using ,i can't tell u🙂 sorry for that.

the hi-freq pwm,not just depend on fets,
the hold sch, the design of pcb,the return,etc..

a tips: look at class-d amp as a nomal amp...

i'll post the pic of freq-respont , plus-res, osc,etc..
perhaps,the pic of pcb

it is a hard work , because i'm not a full menber🙂

i'm a newb here, and my english not well,
i dont(hard to ) understand the rules of this form 🙁

 

[classd_fromru]

Hi
fumac,
looking good 😎
Do you have any results of measurements (THD, SNR) ?

I think direct fet will be better than smd FET in plastic package, but soldering directfet on the pcb is not easy.

(am Russian and my english not very good too )

 

[fumac]

hi big-brother🙂

well come to my Topic

i will post the results of measurements now🙂🙂

and waiting🙂🙂 i'm doing with the pictures

about 20pics


i'm designing the new PCB with directfet,up to 350w rms🙂🙂

thank u for your advice 🙂🙂

 

[fumac]

pwm base freq

this is the pic of 1Mhz PWM
NO signal input,INPUT PIN not to gnd
POWER:+- 25v DC

 

[fumac]

input 1khz square and sine

input 1khz square and sine (WAVETEK 271)

output imp 6Ohm

JUST ONE LC FILTER

I'VE TRIED ,TWO LC WILL MORE FINE

 

[fumac]

20khz square and sine

input 20khz square and sine (WAVETEK 271)

NOT SO MANY AMPs CAN DRIVER THE 20K so sharp

first time i use 400KHz pwm, the 20khz square just like 20khz sine

if down to below 400K, i cant except🙂(can hear the diffrent)

i'm trying to build another d-amp up to 2MHz, trying

 

[Foxx510]

Will you be selling these modules either in kit or completed form?

Thanks
Adam

 

[Bruno Putzeys]

Feind hört mit.

 

[classd_fromru]

fumac,

Thanks for oscillograms 🙂
But am interesting measurements of perfomance, not the frequency response 😉

A you doing measurements of distortion at 1khz sine??
like this:

http://www.diyaudio.com/forums/showthread.php?postid=1090535#post1090535

 

[fumac]

is coming soon 🙂

is coming soon 🙂
is very slow here🙂

 

[fumac]

distortion at 1khz sine

1khz input

output 27.3V P_P @6r is 15.5w rms

1khz output: 19.6dbv
2khz output :-56.6dbv
DIS :~76.2db(0.017%) @6r 15.5w rms

i have no a great sound card, just use HP

 

[fumac]

Bruno Putzeys Feind hört mit.
---------------
wellcome🙂
but i dont konw what u say🙂


Foxx510 Will you be selling these modules either in kit or completed form?

Thanks
Adam
------------
will be kit and completed
but i have no Interested to be a seller,
i'm finding PartnerS to sell it🙂
callme skype:huygens_wireless

 

[fumac]

a Static output

a Static output Voltage PIC
just 0.175v
the LC is Suitable
I HAVE TEST SOME OTHER CLASS-D AMP
THE Static output Voltage IS HIGHT TO 0.5~3V
i think it will Interference the high speaker,and EMC

 

[fumac]

0~25khz freq respon

this is the 2db/div
20~20K +- 1db