Best Deadtime Delay Circuit in Class-D

[Pabo]

Peranders

Hello there!

I have seen you around here, I sure liked your designs as well

The subwoofer amp is not the hi end amp I was telling you about. The hi end amp is called VCCA and is based on a more complex two loop design. We are continuously improving VCCA and have increased the linearity so that the THD is down at about 0,002% at 1W/1kHz and 0,01% at high frequencies. The interesting part is that he distorsion is allmost unchanged with power. For example at 50W/1kHz the THD is about 0,005%. Next DIY gettogether I will bring a stereo VCCA amp.

Thoriated

You may be right about that.

 

[phase_accurate]

Thoriated

You may be right about that.

I agree about that too altough care has to be taken for not messing this up again due to EMC etc.
OTOH deadtime has indeed some effect but IMO not as much as some people claim who directly compare the deadtime to crossover distortion in class-AB amps.

Another advantage of class - d: It drives reactive loads with ease. This is of course depending on frequency, feedback/output-filter topology and PSU topology. But at low frequencies they are a clear winner in this respect.

Regards

Charles

 

[peranders]

Peranders

Hello there!

I have seen you around here, I sure liked your designs as well

The subwoofer amp is not the hi end amp I was telling you about. The hi end amp is called VCCA and is based on a more complex two loop design. We are continuously improving VCCA and have increased the linearity so that the THD is down at about 0,002% at 1W/1kHz and 0,01% at high frequencies. The interesting part is that he distorsion is allmost unchanged with power. For example at 50W/1kHz the THD is about 0,005%. Next DIY gettogether I will bring a stereo VCCA amp.

Watch out Lars and the "ICE"-team, here is pabo

I can't wait.... to see your amp.... not a sneak preview...?

 

[kASD]

Commentable Thoughts

Only my mother calls me Per-Anders.

BUT AmPmAn will Call u
P-E-R-A-N-D-E-R-S THE FRIEND
I am testing my Prototype using 100nS deadtime , IR2110 , IRF540N with Full Bridge-Class-BD Trilevel modulation and i will post the photos too. Besides this i also want to look at PABO's amp also.

compliments
ampMAN

 

[kASD]

Commentable Thoughts

I agree about that too altough care has to be taken for not messing this up again due to EMC etc.
OTOH deadtime has indeed some effect but IMO not as much as some people claim who directly compare the deadtime to crossover distortion in class-AB amps.

Another advantage of class - d: It drives reactive loads with ease. This is of course depending on frequency, feedback/output-filter topology and PSU topology. But at low frequencies they are a clear winner in this respect.

Regards

Charles

Hi Charles Nice to see u too.
So whats ur suggestion on implementing the deadtime circuit choices. Secondly u mentioned about the reactive loads which are easily driven by class-D amps than class-AB.PLZ CommenT

Compliments AmPmAn

 

[zic]

Cmos delay

but if I want to get the Delay by using Cmos IC,then what shoud I do?

 

[phase_accurate]

The following is easily done in CMOS but a little unpredictable.

Regards

Charles

 

[ChocoHolic]

...hm, during my last examination I came to the conclusion that adjusting the dead time with an RC-RD circuit for the gate drive is pretty fine. This allows to adjust the dead time with quite acceptable thermal drift and further on the external gate-source capacitor allows to control the dead time and also di/dt commutation speed as well. Furtheron it is providing a low hf gate drive impedance, which is reducing trouble from the MosFet's parasitic drain-gate-capacity.

 

[IVX]

Yeah, and why we shall purchase irs21955 for $5, if can buy simplest driver for $.5 and next adjust any dead time.