Class D with GaN FETs & IC PE29102 (GaN FET) driver

Hello

Class D Audio Using the PE29102 driver IC

here reference design

https://www.psemi.com/pdf/app_notes/an72.pdf

Class-D Audio Amplifiers


GaN FETs Devices for audio applications. coming in the market.

GaN FETs are preferred as the switching devices because they offer significant advantages over
MOSFETs. Because GaN FETs are faster, smaller and do not have a body diode, they have fewer switching
losses versus conduction losses, resulting in superior linearity and efficiency


Does somebody already have expereince ?
 
Have you seen the TO-247 offerings from Transphorm? They look fairly routine to apply -- from a mechanical standpoint, at least.

DigiKey stocks several p/n's in the $9 - $14 USD range, 650 Volt, 30 Amp for one.

Driving and snubbing them properly looks like it could be a little tricky, but probably not as bad as SiC. Definitely read all the mfg's App Notes you can get your hands on.

Regards,
Rick
 
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Have you seen the TO-247 offerings from Transphorm? They look fairly routine to apply -- from a mechanical standpoint, at least.

DigiKey stocks several p/n's in the $9 - $14 USD range, 650 Volt, 30 Amp for one.

Driving and snubbing them properly looks like it could be a little tricky, but probably not as bad as SiC. Definitely read all the mfg's App Notes you can get your hands on.

Regards,
Rick

TO247 Gans for Class D design..... High Power Gan Fets have Qg 18 thats very good, this beat many mosfets

I think with GAN Fets, Class D have 99 % efficiency

amp will running very cool and need only small haetsink

Technics using in NEW High END amps Gan Fets


I think improvement THD and Sound, with Gan Fets

because Dead Time 5ns is possibile , impossibile with mosfets

Psemi driver IC offer 5ns dead time with Gan Fets


I never have test it, but I think its time to try

we can take fullbridge proven Class D DIY design and move to GAN,, lets try what happened
 
The trick with GaNs is that they are a lot harder to place on a circuit board. You can put together surface mount stuff pretty easily with a normal soldering station but all the GaN transistors I've seen require that you flow the solder to make connections to them.


They are about the hardest devices to surface mount, perhaps worse than BGAs.


I bought a couple of EPC2903 modules for this reason as they have done the hard work and mounted a half-bridge and driver onto a 12mm x 12mm module for you (its still SMT though, just much easier to handle).


Here's my attempt to mount onto a test board:
EPC2903_GaNFET_module.jpg
 
They are about the hardest devices to surface mount, perhaps worse than BGAs.


I bought a couple of EPC2903 modules for this reason as they have done the hard work and mounted a half-bridge and driver onto a 12mm x 12mm module for you (its still SMT though, just much easier to handle).


Here's my attempt to mount onto a test board:
EPC2903_GaNFET_module.jpg


EPC2903_GaNFET is toys, No ! better relax and use TPA3255 for Class D !



We talk about big power Class D, you get 99 % efficiency and 5 ns deadtime

TO-247 TP65H035WSQA 650V GanFET

Key Specifications
VDS (V) min 650
V(TR)DSS (V) max 800
RDS(on) (mΩ) max* 41
QRR (nC) typ 178
QG (nC) typ 24


I think we can upgrade existing big power DIY Class D circuits with GanFET

Fullbridge / Halfbridge, ....improve performance and decrease heat - 30 %


"ucd 25 watts to 1200 watts using 2 mosfets - diyAudio"
 
Have you seen the TO-247 offerings from Transphorm? They look fairly routine to apply -- from a mechanical standpoint, at least.

DigiKey stocks several p/n's in the $9 - $14 USD range, 650 Volt, 30 Amp for one.

Driving and snubbing them properly looks like it could be a little tricky, but probably not as bad as SiC. Definitely read all the mfg's App Notes you can get your hands on.

Regards,
Rick


:cool:
 
Hello


GaN FETs are preferred as the switching devices because they offer significant advantages over
MOSFETs. Because GaN FETs are faster, smaller and do not have a body diode, they have fewer switching
losses versus conduction losses, resulting in superior linearity and efficiency


Does somebody already have expereince ?

I don't think linearity matters in a class d amp as the GaN mosfet is in switch mode not linear mode.
 
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Joined 2007
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I have experience with GaN systems parts for high frequency power conversion and can recommend them. You want to avoid conventional leaded or first generation surface mount packages for GaN as the loop inductance reduces switching speed and increases gate overshoot. Using the right gate drive its possible to switch in a few nS. There is a lot of subtle issues to work through to use these parts but here are a few pointers:

1) INTERSIL ISL55110IVZ is a good choice of gate driver
2) Use 4 layer or thin board to get lower loop inductance
3) Optimise via placement for lower inductance
4) Bottom side cooled parts are easier to use as top side parts will break if they are not flat on the board and then clamped with a heatsink.
5) Decoupling needs to be designed for low ground plane impedance to GHz frequencies
6) Instrumentation is very difficult due to very fast rise/fall

GaN Systems
 
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Joined 2007
Paid Member
So, from your experience, the conventional pkgs, TO-220, TO-247, just have parasitics that are too high to achieve the full potential of GaN parts?

Thanks,
Rick

Yes you can not achieve high switching speeds as there is too much overshoot (at the die) due to the lead inductance. This causes premature failure of the device. If you needed to use very high speed gate drive you give up on square waves and use sine wave drive.
 
Yes you can not achieve high switching speeds as there is too much overshoot (at the die) due to the lead inductance. This causes premature failure of the device. If you needed to use very high speed gate drive you give up on square waves and use sine wave drive.

want use GaN TO247 for high power class D to replacing mosfets

not good news,

but Transphorm GaN Power FET Portfolio - Transphorm

offer 650V TO247 GaN for up to 3,5 KW

In this case, how is it possibile to drive TO247 GaN ?

Are you sure only sine wave drive will work with TO247 GaN ?