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Power Management ICs Forum Discussions

The_BOOM
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I'm seeking a very-low-parts-count, galvanically-isolated DC/DC converter, 40 Watts, 12-24 Volts In, 4-9 Volts out.

Something like the LM25184 (which does it for about 10 parts), but need 40 watts.

We need to buck/stepdown.

Input: 12 V to 24 V

Output: 4 V to 9 V @ 40 W

Note: We actually want 4 x 10 W outputs.

It's important for the outputs to be isolated from each other.

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SC
Moderator
Moderator 10 likes received 25 replies posted 10 solutions authored
Moderator

Hi,

Thanks for posting at the Infineon community.

As per your design requirement the integrated controller + FET solution should be capable to handle power dissipation well within the thermal limit due to high RMS currents flow from low supply input (12v to 24v). 

Infineon portfolio having internal driven FET based Control IC, for offline application at below link.

https://www.infineon.com/cms/en/product/power/ac-dc-power-conversion/ac-dc-integrated-power-stage-co...

But for your requirement we recommend you to use an external driven FET-based controller from the Infineon portfolio. 

Finally, it is a trade-off between component count and power delivery when choosing controller.

Thanks,

SPCH.

The_BOOM
Level 2
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Level 2

Thx! Note, we need 40 Watts continuous. Will your solution deliver that?

Can you share a reference design and part numbers?

On the selector you linked, i checked filter to "flyback", and unchecked "Non-isolated flyback". i set  40W+ "max".

i got one preferred part marked "flyback".

ICE3BR0665J

The reference design in the datasheet for that part includes one or more sections that we don't need, such as the AC input rectifier (since our input is DC). Can you share a DC/DC design?

The eval board for this part has about 40 parts (not counting the AC input section), which is 30 more parts than we're aiming for.

30W 16V Evaluation board using ICE3BR0665J

The selector also gave this other preferred part. 

ICE5AR0680AG



 

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SC
Moderator
Moderator 10 likes received 25 replies posted 10 solutions authored
Moderator

Hi,

Thanks for posting at the Infineon community.

For your application we recommend you to use an external Driven FET-based solution since the RMS currents at the input side are significantly high as compared with an Offline (Universal AC Input) Flyback converter. Increased RMS currents can cause thermal challenges.

Below is the reference link for Infineon portfolio Flyback controllers which will drive external FET. Application notes were also available on the same page of provided link.

https://www.infineon.com/cms/en/product/power/ac-dc-power-conversion/ac-dc-pwm-pfc-controller/pwm-qr...

https://www.infineon.com/cms/en/product/evaluation-boards/demo_5asag_60w1/

https://www.infineon.com/cms/en/product/power/ac-dc-power-conversion/ac-dc-pwm-pfc-controller/pwm-qr...

https://www.infineon.com/cms/en/product/power/ac-dc-power-conversion/ac-dc-pwm-pfc-controller/pwm-ff...

The_BOOM
Level 2
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Level 2

Hello,

The ICE5QSBG reference design is about 30 parts (not counting the AC rectifier, which we don't need, or snubber). Is there a DC/DC converter with this part using much fewer parts? If not, then the  parts-count  is too high for our application. Is a no-opto design possible?

User20327_0-1651833423133.png

The ICE2QS03G and ICE3AS03LJG reference designs are each about 20 parts (not counting the AC rectifier or snubber). That is better, but still more parts than we're targeting.  Is a no-opto design possible? Any other sections or parts we can eliminate?

User20327_0-1651846529770.png

We seek radical simplicity.

We can tolerate significant ripple, drift, and overshoot, as long as the output remains between 4 V to 9 V. Does that offer any opportunities to eliminate parts or sections?

Thx!

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SC
Moderator
Moderator 10 likes received 25 replies posted 10 solutions authored
Moderator

Hi,

Thanks for posting at the Infineon community.

Since you are looking for a low component count, we recommend you look into OPTIREG switcher TLE8386-2EL.

Below are the links for your Reference.

https://www.infineon.com/cms/en/product/evaluation-boards/48v-flyback-demoboard/

https://www.infineon.com/dgdl/Infineon-Z8F70258391_12V_1A_Flyback_Converter_Gen2-ApplicationNotes-v0...

https://www.infineon.com/dgdl/Infineon-TLE8386-2EL-DS-v01_00-EN.pdf?fileId=5546d46258fc0bc1015969d28...

SPCH_0-1651914557094.png

 

Thanks,

SPCH

The_BOOM
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Level 2

Thx for that! But the TLE8386-2EL appears to be a boost/stepup device.

We need to buck/stepdown.

Input: 12 V to 24 V

Output: 4 V to 9 V @ 40 W

Note: We actually want 4 x 10 W outputs.

It's important for the outputs to be isolated from each other. 

I'm thinking the lowest-part-count design may be a device or topology that outputs 40 watts of non-isolated, unrectified power, and then a separate transformer+rectifier for each output.

One of these?

https://www.infineon.com/cms/en/product/power/dc-dc-converters/switching-regulators/optireg-switcher...

https://www.infineon.com/cms/en/product/power/dc-dc-converters/switching-regulators/optireg-switcher...

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SC
Moderator
Moderator 10 likes received 25 replies posted 10 solutions authored
Moderator

Hi,

Thanks for posting at Infineon Community.

The OPTIREG switcher TLE8386-2EL that we suggested can be used in the Boost/ Step-Up application as you said correctly. At the same time, it can be used for Flyback and Buck converter applications. In the previous reply, we added all supporting links which will explain the usage in the Flyback application you can refer to the same.

 

SPCH_1-1652086536464.png

 

Thanks,

SPCH