|
|||||||
| Home | Forums | Rules | Articles | Store | Gallery | Blogs | Register | Donations | FAQ | Calendar | Search | Today's Posts | Mark Forums Read | Search |
| Class D Switching Power Amplifiers and Power D/A conversion |
|
Please consider donating to help us continue to serve you.
Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving |
|
|
|
Thread Tools | Search this Thread |
|
|
#51 |
|
diyAudio Member
Join Date: Sep 2009
Location: Bucharest
|
is true, this is the first layout in class D amplifier and may not be very properly designed , this is the reason for which are here , in Romania is no interest to this class
|
|
|
|
|
#52 |
|
diyAudio Member
|
To start converting this layout into something capable of switching some current fast reliably I suggest:
- Add a continous ground plane that may be connected to the negative or the positive rails rather than ground. Single sided PCB won't be up to the job. - Remove the 2.2k gate resistors, they are not required at all and make the layout more complex by taking very useful space. - Group the MOSFET in close lo/hi side pairs. - Add 100n SMD capacitors from low side MOSFET sources and high side drains to ground plane (or from low side sources to hi side drains if the plane is a rail). - Add more 470u 100V capacitors. Capacitors tend to exhibit 1nH parasitic inductance per mm of lead spacing. Paralleling many divides inductance by the amount of them. - Add LC filters to supply rail inputs to prevent the HF ripple due to high current switching from reaching wirings. - IRFP260 can't go very far once the body diodes start conducting. Suitable MOSFET are the much newer IRFB4227 and the improved IRFB4127. - TO-247 MOSFET are good when power dissipation is high (class A or AB), but class D is not about that, it's about low parasitics and fast switching. TO-220 does that much better. See lead inductance data on most IR datasheets. - Consider replacing the two driver ICs by NPN and PNP SMD buffers near the gates, the inductance of the long gate track results in all MOSFET not switching at the same time. There are good high current low voltage bipolars in SOT-23. 3-4A peak are required for fast turn off. - Add diodes from IR chip outputs to their rails to prevent latchup when the outputs are forced to exceed the rails. - Add a diode from VS to COM to prevent the IR chip from failing due to excess negative spikes on VS. These diodes should be SMD to keep things small and low inductance. - The parasitic inductance of the RC snubbers from the switching node to the rails matters a lot, the optimum value makes the snubber more efficient since it becomes a RLC resonator that can be tuned at the frequency where MOSFET capacitance and package and supply parasitic inductances resonate. Too high inductance and the snubbers will do nothing. Too low inductance makes them less efficient but it's not that bad. With a highly optimized layout and supply capacitors arrangement I'm getting 36A peak per IRFB4227 reliably. Your layout would be nice as a class AB amplifier, but the usual visual symmetry is worth nothing for high speed switching. Anyway, I think you are going in the right direction by daring making a layout an publishing it to get some feedback (that's why I'm giving you these hints )
__________________
I use to feel like the small child in The Emperor's New Clothes tale
Last edited by Eva; 24th November 2009 at 11:13 AM. |
|
|
|
|
#53 |
|
diyAudio Member
|
On this thread you can see a layout probably not good enough for class D giving problems and a good one for the same chip:
TPA3122 works fine on battery - starts clicking on powersupply.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
|
|
|
|
|
#54 |
|
diyAudio Member
Join Date: Jan 2008
|
|
|
|
|
|
#55 |
|
diyAudio Member
|
But this is a commercial product
![]() (Why so many fans? Is there really so much heat to get rid of? )
__________________
I use to feel like the small child in The Emperor's New Clothes tale
|
|
|
|
|
#56 | |
|
diyAudio Member
|
Quote:
it seems that these guys from Thailand (Detex and now this Digitclass thing) have no idea how make switching efficient. And look at these SMPSs, so big so expensive for the claimed output power, where smarter/more efficient/cheaper design can do it... And I don't talk about the air flow, with fans pulsing air 90 degrees perpendicular of each other and with large heatsink blocking the flow
|
|
|
|
|
|
#57 |
|
diyAudio Member
Join Date: Jan 2007
|
Hello Tiwa,
your amps look very nice. |
|
|
|
|
#58 | |
|
diyAudio Member
Join Date: Dec 2003
Location: Munich
|
Quote:
Many people here appreciate your support. And it is nice to see that you are going on to give it, even if there are to many guys who are not like DJ_DUMY and who are just sucking information in order to copy and sell, without any own technical engagement. |
|
|
|
|
|
#59 |
|
diyAudio Member
Join Date: Feb 2008
|
hi tiwa
greetings does this site sell kits .very nice products but in thai thanking you andrew lebon |
|
|
|
|
#60 |
|
diyAudio Member
Join Date: Dec 2008
|
dear sir
i want pcb desin this amp irs2092_6kw. lay my mail id karat-ufa@mail.ru please send this address |
|
|
| Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
| Thread Tools | Search this Thread |
|
|
|
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Irs2092 | luka | Class D | 37 | 31st January 2012 05:45 PM |
| IRS2092 on breadboard | rob mullen | Class D | 31 | 27th November 2010 01:24 AM |
| Another amp with IRS2092 | mag | Class D | 23 | 18th June 2010 08:25 PM |
| IRS2092 AMP help | yaronshani | Class D | 3 | 29th January 2010 03:29 PM |
| IRS2092 help! | yudi02 | Class D | 2 | 11th October 2009 04:30 AM |
| New To Site? | Need Help? |
| Page generated in 0.11818 seconds (79.52% PHP - 20.48% MySQL) with 11 queries |