Class D - Half Bridge vs Full Bridge

[aarmath]

My first thread (Hoping it will be a great discussion) on ASR!

Why is the Full Bridge feature in select Class D modules not touted upfront as a feature?
From what I have read Full Bridge has fundamental positive attributes like efficient use of source voltage for far higher power output compared to a half-bridge topology.
Apart from that there are inherent benefits like rejection of Bus Pumping, shootout current.
& yet I don't see that being discussed or featured by manufacturers in their product specs.

Or is it that the Full Bridge/Bridge-Tied-Load aspect is a vanilla feature that is already widespread in Class D modules & is taken for granted.?

For example - (And this is what prompted my post) - In one of the sub-forums a poster commented that the ICEPower 700AS (1 & 2) module is Full-Bridge.

In closing, I understand that Full Bridge is a relatively expensive proposition. But does the cost outweigh the fundamental benefits?

 

[samsa]

I gather Hypex nCore and Purifi modules are half-bridge?

 

[boXem]

I gather Hypex nCore and Purifi modules are half-bridge?

Indeed, they are half-bridge, but working on dual rails, at the opposite of most ICs working on single rail.

 

[kaka89]

Nuprime ST-10 is full bridge

https://nuprimeaudio.com/product/st-10/?v=b0c4bc877c29

 

[Vini darko]

Check this explanation on the topic of full versus half bridge. Begins @8 mins.

 

[aarmath]

Fantastic! Thank you Kaka89 & Vini Darko for the informative posts.
I hope more ASR folks contribute such kind of constructive links on Full Bridge amps.

 

[aarmath]

Indeed, they are half-bridge, but working on dual rails, at the opposite of most ICs working on single rail.

Thanks on the post Fred!
What do you mean by dual rails? It sounds borderline Full Bridge Mode

 

[boXem]

Thanks on the post Fred!
What do you mean by dual rails? It sounds borderline Full Bridge Mode

Supply rails.
When single rail, each half bridge has a voltage span between ground and the rail voltage.
When dual rails (which are usually symmetrical to GND), each half bridge has a voltage span between the two rails voltages.

 

[aarmath]

Supply rails.
When single rail, each half bridge has a voltage span between ground and the rail voltage.
When dual rails (which are usually symmetrical to GND), each half bridge has a voltage span between the two rails voltages.

Thanks for the explanation matw!
Am I right in presuming that dual rails would be a prerequisite for Full Bridge Class D amps?

 

[boXem]

Thanks for the explanation matw!
Am I right in presuming that dual rails would be a prerequisite for Full Bridge Class D amps?

No . The 4 combinations are possible. The most tricky is single rail half bridge since the average is at Vrail/2, you need to add a few components to remove the DC part of the output. In the 3 other cases, the average is at 0V. For full bridge, each half works in phase opposition.

 

[dougi]

I have a TACT/Lyngdorf SDA-2175 power amp, which has 35V DC referenced to ground on the speaker outputs. I assume then it must be half-bridge? After building a amp dummy load last weekend I will be tentatively testing it this weekend. My audio interface is AC coupled so I shouldn't blow that up. I tested my old Krell KAV-300i integrated without any dramas so I hope for no problems with the Lyngdorf! (oh yes this is my first post)

 

[aarmath]

I have a TACT/Lyngdorf SDA-2175 power amp, which has 35V DC referenced to ground on the speaker outputs. I assume then it must be half-bridge? After building a amp dummy load last weekend I will be tentatively testing it this weekend. My audio interface is AC coupled so I shouldn't blow that up. I tested my old Krell KAV-300i integrated without any dramas so I hope for no problems with the Lyngdorf! (oh yes this is my first post)

Welcome aboard mate! Please do post your observations on this thread, I reckon it would be pretty interesting.