UCC24610: Using for Forward

ACGUY

Part Number: UCC24610
Other Parts Discussed in Thread: TPS51604, UC2715, PMP3162, UCC27511, UCC24612, TINA-TI

Hello E2E,

I came up with full secondary side synchronous control using UCC24610 by see fig.23.
I drew the simple schematic, please see it.
We necessary dead time settings firture because reduce the shoot through current.
I thought that use UC2715 or TPS51604 for gate timming contlorl would reduce the shoot through current.
Pulse trigger is Drain voltage of primary side FET.

Does TI concerned about this usage?
Please specialist opinion.

Best regards,
ACGUY

over 4 years ago

0 Benjamin Lough over 4 years ago

TI__Mastermind 26225 points

Hi ACGUY,

I would suggest using the transformer windings and feeding to external gate drivers. No need for the UCC24610's. Take a look at PMP3162:http://www.ti.com/lit/df/slur815/slur815.pdf. This is an active clamp forward with synchronous rectification. The SR FETs use the transformer winding voltages fed to two UCC27511 gate drivers.

Best Regards,

Ben Lough

0 ACGUY over 4 years ago in reply to Benjamin Lough

Guru 11170 points

Hello Ben,

Thank you for reply. I know the PMP3162.
However, it may be that FETs are turned on simultaneously. If there is no dead time, the switching frequency cannot be increased. I think that to achieve high-speed response performance, it is necessary to secure dead time.

Could you let me know about a synchronous rectification forward solution that eliminated simultaneous FET ON?

Regards,
ACGUY

0 Benjamin Lough over 4 years ago in reply to ACGUY

TI__Mastermind 26225 points

Hi ACGUY,

Take a look at this white paper. It discusses using a UCC3580 which has an adjustable delay to control the SR of a forward converter:http://www.ti.com/lit/ml/slup120/slup120.pdf.

Best Regards,

Ben Lough

0 ACGUY over 4 years ago in reply to Benjamin Lough

Guru 11170 points

Hello Ben,

I'd like to simuration for UCC24610 and UCC24612 on TINA-TI. Does TI able to provide sim-models?

Regards,
ACGUY

0 Benjamin Lough over 4 years ago in reply to ACGUY

TI__Mastermind 26225 points

Hi ACGUY,

UCC24612 simplis simulation model can be found at the bottom of this page:http://www.ti.com/product/UCC24612/technicaldocuments

A simulation model for UCC24610 is not available unfortunately.

Best Regards,

Ben Lough

0 ACGUY over 4 years ago in reply to Benjamin Lough

Guru 11170 points

Hello Ben,

Thank you for information. I installed SIMPLIS free version, it was can't run. Because limit for nodes. Licenced version is very expensive, I can't buy it. Does TI able to run the simulation on my behalf?

I want to do know that how much the shootthrough current using UCC24612 at secondary-SR for forward.

Vin=10V
Vout=5V
fsw=100kHz

Regards,
ACGUY

0 Benjamin Lough over 4 years ago in reply to ACGUY

TI__Mastermind 26225 points

Hi ACGUY,

Apologies for the long delay. If you could send me your file, I will run the simulation for you.

Best Regards,

Ben Lough

0 ACGUY over 4 years ago in reply to Benjamin Lough

Guru 11170 points

Hi Ben,

Thank you for your cooperation. I attached schematic file.
(Sorry. I can't determine if this schematic is correct.)

[Request]
Want to do use the UCC24612 at secondary side full-synchronous rectifier circuit.

[Conditions]
fsw=90kHz-110kHz (center 100kHz)
Duty=50%
Vout=5V
Iout=10A

[Concerns/Confirmation]
Existence for shoot through current for secondary FETs at switching. (Important)
Pulse width and peak for shoot through current.

Please check them.

Best regards,
ACGUY

UCC24612_1_SIMPLIS_TRANS.zip

0 Benjamin Lough over 4 years ago in reply to ACGUY

TI__Mastermind 26225 points

Hi ACGUY,

I've been doing some tweaking to the simulation over the past several days. Currently I do see both SR gates are on for a brief period in each switching cycle. Below the blue waveform is the free wheeling SR Vgs and the yellow waveform is the forward SR Vgs.

Best Regards,

Ben Lough

0 ACGUY over 4 years ago in reply to Benjamin Lough

Guru 11170 points

Hello Ben,

Thank you for your cooperation.
For example, if using winding voltage switching as a trigger for UCC24610 gate-off, is the figure below appropriate?
SYNC-pin capacitor is for device turn on delay. Dead time is adjusted by cap that there is between SYNC to GND.

Please let me know your opinion.

Regards,
ACGUY

0 Benjamin Lough over 4 years ago in reply to ACGUY

TI__Mastermind 26225 points

Hi ACGUY,

I think the capacitors on the SYNC pin wont be necessary, this will just delay the turn off of the SR MOSFET gates. I would suggest placing a capacitor in series with the sync resistor instead.

Best Regards,

Ben Lough

0 ACGUY over 4 years ago in reply to Benjamin Lough

Guru 11170 points

Hi Ben,

Thank you for your opinion.
>> I would suggest placing a capacitor in series with the sync resistor instead.
Could you show me that schematic? And, do you know how to simulate for UCC24610?

If we can prove to adjust or set for dead time(or ON delay) of UCC24610s at secondary full-syncronous rectification at forward-topology that we can drive out competitor from our customer's boards.

Best regards,
ACGUY

0 ACGUY over 4 years ago in reply to Benjamin Lough

Guru 11170 points

Is this it?

0 Benjamin Lough over 4 years ago in reply to ACGUY

TI__Mastermind 26225 points

Hi ACGUY,

Your schematic looks correct. We don't have a simulation model for UCC24610 unfortunately.

Best Regards,

Ben Lough

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UCC24610: Using for Forward