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Ideal bridge rectifier GB

Saligny.jpg


I had a look on the market, did not find one, so we built one. :)
We have designed a small form synchronous rectifier, aka ideal bridge, using modern ultra low Rdson mosfets.
It started as a small side project, but the results are so good that we want to put this in production and make it a standard product.
The advantages of such bridge are very well documented:
Active rectification - Wikipedia
http://www.ti.com/lit/wp/snva595a/snva595a.pdf
Synchronous Rectifier Circuit | Active Rectifier | Radio-Electronics.Com
http://peufeu.free.fr/audio/alim_mos_diode/


Linear product presentation.
https://www.youtube.com/watch?v=x74SSPgKiNA

While this video is about automotive product, the principle is similar.
https://www.youtube.com/watch?v=X5qFJ5XNi9A



Specifications:
- operates from DC to 600Hz
- AC operating voltage 6Vac to 51Vac
- DC operating voltage 9Vdc to 72Vdc
- Iq = 1,5mA
- continuous load current up to 16A or more depending on mosfet configuration.

Do not use centre taped transformers (and centre taped used as main reference ground).

The price will start from 35euro and go down with volume as we get parts in lower price.
Up to 100 units - 35 euro
Up to 200 units - 30 euro
Over 200 units - 25 euro

GB google spreadsheet is open till 1st March included
https://docs.google.com/spreadsheets/d/144EP7ZezFLFgZeNq8q8LCgoa5Lb6z94TKbopFC7S6aw/edit?usp=sharing

Regards,
Tibi
 
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Compared with a diode bridge Saligny (ideal bridge) will deliver 1,5V more.
Here is thermal comparison at same output 8V and load 500mA.

Regards,
Tibi
 

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If you fight with power loss in your class A amplifier rectifier, than Saligny can help you.
If you want better dynamics and response in your class AB amplifier, than Saligny can help you.
If you want to get rid of diode switching noise, than Saligny can help you.
If you want to make your amplifier more green, than Saligny can help you.
If you want to contribute to climate change, than Saligny can help you.
If you want something cool, than Saligny can help you.

:D

Regards,
Tibi
 
AX tech editor
Joined 2002
Paid Member
No I mean, if you switch on the equipment, there will be a one-time inrush current to charge the empty capacitor. That can be many tens of Amps. Normally the MOSFETs have a single pulse current rating, and a repeated pulse rating.
Are you willing to give the MOSFET types? Through PM, confidential if you want.

Jan
 
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There was a very positive buzz on this forum about the combination of LT4320 and the GS61008T.

The idea of sync rectification for audio sounds great in theory but i have no idea what is sounds like in an actual amp. Sometimes great ideas translate into great sound, but sadly not often.
 
There was a very positive buzz on this forum about the combination of LT4320 and the GS61008T.

The idea of sync rectification for audio sounds great in theory but i have no idea what is sounds like in an actual amp. Sometimes great ideas translate into great sound, but sadly not often.


Thank you, analog_sa ! GS61008T is an impressive device.

Regards,
Tibi
 
AX tech editor
Joined 2002
Paid Member
You can always feed a bridge with DC. Normally it doesn't make much sense but is does work fine.

Edit: 51VAC is RMS which is 1.4 X DC, ~ 72V...

The synchronous rectifier generates an internal source that is used to switch on the MOSFET as soon as the Vds starts to go up after zero crossing of the input voltage.

You could also click the link the OP has given ;-)

Jan
 
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Founder of XSA-Labs
Joined 2012
Paid Member
Interesting timing as Janhofland, myself and AKSA have just designed an active bridge using this chip for making 5A continuous load ideal bridge rectifier for a large Class A amp in order to reduce the huge thermal losses from a traditional diode bridge at these kinds of current. I ran across the LT4320 chip about 3 weeks ago. Board still needs to be ordered and will test soon.
 
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Founder of XSA-Labs
Joined 2012
Paid Member
Maybe you should explain a bit about synchronous rectifiers, not everyone will be up to speed, and realize the benefits of rectifier diodes with zero threshold.

Jan

A good explanation is here:
LT4320 Ideal Diode Bridge Controller Cuts Power Dissipation, Improves Efficiency | Power Electronics

One thing I am unsure of, is how the transients of the resulting sawtooth wave looks after the bulk cap? Does it even look like a diode sawtooth? Or will it be a total mess? Although, it can't get much worse than a sharp sawtooth in terms of audio harmonic generation.
 
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