QR Flyback Converter for DC-DC buck action

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Hasan2021
Level 1
Level 1
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Hi there,

I am looking for a customized design where good power solution can be applicable.

My aim is to develop a DC-DC sutable toloplogy ( flyback, buck, isolated ,..so on) converter with following parameter,

INPUT: 250 to 650 VDC

OUTPUT: 24V/5A , 5V/3A, 12V/2A

 How about  quasi resonant flyback  converter topologies ? 

https://www.infineon.com/dgdl/Infineon-Design_guide_CoolSET_QR_ICE2QRxx65-80x-AN-v01_01-EN.pdf?fileI... 

Can you suggest  anything within this power range?

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1 Solution

Hi,

If separate power supply is acceptable, we can suggest the following (mainly driven by the 650VDC input and flyback requirement):

24V / 5A (120W)

ICE2QS02G + 900V MOSFET (e.g. IPW90R120C3)

 

Combine 5V/3A (15W) and 12V/2A (24W) - Total 39W

ICE2QS02G + 950V MOSFET (e.g. IPD95R450P7)

 

Hope that helps.

View solution in original post

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13 Replies
PL21-SMPS-PMG
Employee
Employee
5 likes given First like given 5 sign-ins

Hi,

With an approximate power of ~160W, do you require a PFC stage? Do you intend to implement any synchronous rectification on the secondary side?

Are you able to share what kind of load (e.g. motor, display & etc) is intended for this power supply?

Thanks

Dear Sir,

Thank you to participate in this thread.

You can suggest for PFC.

This converter should be use for battey charger or DC recloser in DL line.

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Hello,

I think for 5V/3A, 12V/2A meaning that 15W and 24 W   ICE2QR type  IC is applicable.

At document  DN 2013-01  ( Design Guide for QR Flyback Converter) page 5 its written that "Therefore it
is not recommended for higher power, wide range designs exceeding 65W-100W, unless cost is a secondary factor and some other possible benefit, such as use of synchronous rectification on the secondary, is critical to system requirements." 

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Hi,

The concern with ICE2QRxxxx is that, it's integrated with 800V MOSFET while your requirement is 650VDC input. As such, factoring in reflected voltage and leakage spike typical in a flyback topology, 800V is insufficient or limited margin.

Just to check, are you looking for a power supply with 3 output or 3 separate power supply?

Thanks

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Yes. Well noticed.  Separate power suppy is logical in this regards.

15W and 24 W can be considered separately.

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Hi,

If separate power supply is acceptable, we can suggest the following (mainly driven by the 650VDC input and flyback requirement):

24V / 5A (120W)

ICE2QS02G + 900V MOSFET (e.g. IPW90R120C3)

 

Combine 5V/3A (15W) and 12V/2A (24W) - Total 39W

ICE2QS02G + 950V MOSFET (e.g. IPD95R450P7)

 

Hope that helps.

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Dear Sir,

Yes those couple works well.

Lets study your datasheet.

If you have any EVM board, feel free to mention here. 

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Hi,

We do not have a EVM that matches your requirement exactly, so it's going to be bits and pieces of it to illustrate different point using different boards.

To get an overview of how ICE2QS02G perform in a typical 85~265Vac input specification, you can take a look at this 80W application note.

To get a feel on how a cross-regulation going to work in the 39W whereby both 12V and 5V output are combined, you can take a look at this 42W design. Ignore the controller and the MOSFET.

Lastly, to illustrate a requirement with high input voltage, you can take a look at this 33W design for hints on the input stage. Once again, ignore the controller and the MOSFET.

Hope that helps.

Dear Sir,

Thank you again to provide suitable informations.


To get an overview of how ICE2QS02G perform in a typical 85~265Vac input specification, you can take a look at this 80W application note.

 

Yes I did see 80w application note , but does it applicable for DC input? 

Lets think 12v and 5 v separately.

33W design shows AC input.

Kindly make sure for DC input range. I will order your product.

 

 

 

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Hi,

For example, that 80W board based on 85~264Vac, you can apply a DC input into the L & N with polarity taken care by the bridge rectifier. What you need to take care is to avoid inputting a DC voltage higher than 375VDC as the bulk cap (C1) used on the board is RATED for 400VDC.

Likewise for the 33W design, however, this design has catered for a higher VIN till 792VDC. You will noticed that there are 2 unit of bulk cap (C13 and C13A) connected in series to support higher VIN.

Thanks

I think bridge rectifier should remove in this case, take a look at it,

dc_input.PNG

 

33W design can also modify in this case right? Those bulk cap should be raise upto 650v. 

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Yes, for DC input design, you can remove the bridge rectifier.

Yes, you need to take care of the bulk cap voltage rating according to your maximum input voltage design. When we design our eval boards, we tend to choose components that are easily available and hence, 2 units of 400V bulk cap were selected for the design.

There maybe 500V and above rating, however, sourcing it for eval board purposes may not be that easy.

Thanks.

Thanks to reaching out.

I need to set parameters of the design according to the datasheet you have provided. Everything looks fine but customized transformer need to manage.

For the high voltage design I am considering Cap value with 0.22uF/1000V.

In my input design what should be the value of L? Do you have any idea to calculate?

 

 

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