Does TI have similar reference design for customer ?

Jimmy WANG

Genius 4035 points

Other Parts Discussed in Thread: UCC28600, UCC28630

Hi team,

Does TI have a similar reference design for customers? Customer want to cost down in new project.

The customer uses MS1004SH to design a peak power solution. schematic as attached

AC: 220V(+-20%)

Muti output: Vo1=32V@8A (<2S) ,(4A) (<60S)

Vo2=15V@0.1A

Vo3=12V@0.1A

Vo4=15V@2A

Another question is whether MOSFET uses 900V device.

6013.Schematic.pdf

over 2 years ago

0 Jimmy WANG over 2 years ago

Genius 4035 points

I don't think this architecture requires a 900V MOSFET

0 Harish Ramakrishnan5 over 2 years ago in reply to Jimmy WANG

TI__Mastermind 24375 points

Hi Jimmy,

Thank you for the query.

Assuming 220Vac is the max input voltage, the choice of switch is basically going to depend upon the transformer turns ratio. Using turns ratio close to 5 along with tight leakage would help with a lower voltage FET as you say.

Secondly, UCC28600 wil be similar part with QR functionality as MS1004SH. Cost removes potential ACF solutions for these power levels.

I would also recommend UCC28630 which can support these power levels but it is PSR controller, so you might want to check with voltage regulation limits.

There are not any reference designs for this power level but PMP8582, PMP7148 shows multiwinding output control using UCC28600.

Please let us know if you have further questions.

Regards,

Harish

0 Jimmy WANG over 2 years ago in reply to Harish Ramakrishnan5

Genius 4035 points

Hi Harish,

But turns ratio close to 5 will impact efficiency. right? normally, this topology primary FET can use 650V FET?

0 Harish Ramakrishnan5 over 2 years ago in reply to Jimmy WANG

TI__Mastermind 24375 points

Hi Jimmy,

True using a lower turns ratio is going limit the duty cycle and in turn will lead to higher peak currents in the primary side and will increase conduction losses and switching loss at turn off.

Correct, the topology uses 650V device, assuming reflected voltage of 120V, leakage spike close to 80V which will ensure max Vds stress on the switch is contained within 570V and a 650V switch can be used.

Please let me know if you have further questions.

Thank you

Regards,

Harish

0 Jimmy WANG over 2 years ago in reply to Harish Ramakrishnan5

Genius 4035 points

Hi Harish,

base on webench design:https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=93A013D5FE345A7E

The transformer ratio shows below. but as I know that Np number of turns is calculated. so if show ratio as WEBECH.

So is it as full as possible under the winding area of the transformer? Could you share the transformer design tool for me? thanks

0 Harish Ramakrishnan5 over 2 years ago in reply to Jimmy WANG

TI__Mastermind 24375 points

Hi Jimmy,

The specification initially suggested using 32V on the output.

The power designer shows 24V, so there will be variations in the turns ratio. Which transformer design tool you are refering to? I think it will be better to cross check the turns ratio calculated with the UCC28600 excel calculator tool.

With 24V output we can probably get away with a 650V switch with a tight transformer design.

Please let me know if you have further questions.

Regards,

Harish

0 Jimmy WANG over 2 years ago in reply to Harish Ramakrishnan5

Genius 4035 points

Hi Harish,

Customer has 2 spec. so we discuss 24V first. do you have UCC28600 excel tool?

0 Harish Ramakrishnan5 over 2 years ago in reply to Jimmy WANG

TI__Mastermind 24375 points

Hi Jimmy,

Please find the path for UCC28600 excel tool.

https://www.ti.com/product/UCC28600#design-tools-simulation

There is a excel calculator as well as TINA model.

Thank you

Regards,

Harish

0 Jimmy WANG over 2 years ago in reply to Harish Ramakrishnan5

Genius 4035 points

Hi Harish,

So you think turn ratio 5 is better for the design? What Transformer core is popular ? EE42? or PQ35?

0 Harish Ramakrishnan5 over 2 years ago in reply to Jimmy WANG

TI__Mastermind 24375 points

Hi Jimmy,

I think with the 650V option we have to go with the turns ratio of 5. The attached calculator also suggests the same.

UCC28600_calculator.xls

I think E35/21/9 or higher core should be used. PQ32/30 would be the minimum core size.

The following chart from mag-inc helps select the core size.

https://www.mag-inc.com/getattachment/Design/Design-Guides/Transformer-Design-with-Magnetics-Ferrite-Cores/MagneticsTypicalPowerHandlingChart2012.pdf?lang=en-US

https://www.mag-inc.com/Media/Magnetics/File-Library/Product%20Literature/Ferrite%20Literature/Magnetics2013FerriteCatalog.pdf

PQ should be better in terms of shielding of inner coil, takes up lesser amount of area on PCB than E core but might end up being costlier than E core.

Thank you

Regards,

Harish

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Does TI have similar reference design for customer ?