UCC24624: UCC24624 for secondary side synchronous rectification for half bridge configuration

Suraj Sharma

Part Number: UCC24624

Tool/software:

The input transformer is fed with an AC signal of 264V at 30kHz +/- 12kHz ( NOT LLC). Previously we were using half bridge diode rectification to get the output voltage of 48V.Now We want to modify the circuit having 48V output to synchronous rectification.The load power is 9KW. Can i use UCC24626 as it is not LLC. If yes then what should be the implementation step.

9 months ago

0 Manikanta Pallantla 9 months ago

TI__Genius 16155 points

Hi Suraj,

Could you share me the schematic of your circuit? What's the expected conducted duration of the secondary side FETs?

Regards

Manikanta P

0 Suraj Sharma 9 months ago in reply to Manikanta Pallantla

Prodigy 50 points

This is the circuit diagram and we want to change to synchronous rectification on 48V side

0 Manikanta Pallantla 9 months ago in reply to Suraj Sharma

TI__Genius 16155 points

Hi Suraj,

Thanks for sharing the schematic. Could you also share me the waveform shape through the diode rectifiers?

Regards

Manikanta P

0 Suraj Sharma 9 months ago in reply to Manikanta Pallantla

Prodigy 50 points

0 Manikanta Pallantla 9 months ago in reply to Suraj Sharma

TI__Genius 16155 points

Hi Suraj,

By looking at the wave shape of the transformer current, you can definitely use the UCC24624 controller.

Regards

Manikanta P

0 Suraj Sharma 9 months ago in reply to Manikanta Pallantla

Prodigy 50 points

But our primary side is not LLC.Now can i use it?

0 Manikanta Pallantla 9 months ago in reply to Suraj Sharma

TI__Genius 16155 points

Its okay to use UCC24624 here as your transformer currents resembles the LLC secondary currents. What UCC24624 looks for drain to source voltage drop. As long as anti-parallel diode turns on, controller turns on gate pulse.

I just noticed one thing in your waveforms, Why does the transformer current (current through the didoes) going negative (CH 4 and CH 6) ?

Regards

Manikanta P

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UCC24624: UCC24624 for secondary side synchronous rectification for half bridge configuration