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Power Management ICs Forum Discussions

NXTY_Fujioka
Level 2
First solution authored 5 replies posted 10 sign-ins
Level 2

Hi all,
I have a question regarding the use of CoolSET.

Can CoolSET be used as a non-isolated AC/DC buck converter without a transformer?
I don't think it can be done with the QR type CoolSET, but I believe it can be done with the fixed frequency type, am I correct?
And, Can both CoolSET's 5th and 3rd generation products support this usage?

Thanks.

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Pablo_EG
Moderator
Moderator 250 sign-ins 250 replies posted 25 likes received
Moderator

Hello Fujioka-san,

Thank you for posting on Infineon Community.

The fixed frequency CoolSET can be used for non-isolated AC/DC.
The 5th generation can be used for buck topologies.
The 3rd generation is not very suitable due to the high switching frequency.

If you would like to know more about non-isolated AC/DC designs with CoolSET 5th gen, please contact Infineon Sales.

Best regards,
Pablo

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Pablo_EG
Moderator
Moderator 250 sign-ins 250 replies posted 25 likes received
Moderator

Hello Fujioka-san,

Thank you for posting on Infineon Community.

The fixed frequency CoolSET can be used for non-isolated AC/DC.
The 5th generation can be used for buck topologies.
The 3rd generation is not very suitable due to the high switching frequency.

If you would like to know more about non-isolated AC/DC designs with CoolSET 5th gen, please contact Infineon Sales.

Best regards,
Pablo

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NXTY_Fujioka
Level 2
First solution authored 5 replies posted 10 sign-ins
Level 2

Hi Pablo-san, 

Thank you for your answer.

Please let me check just to be sure.
Can CoolSET be used as a non-isolated AC/DC buck chopper as shown in the attached Figure?

Also, I think Coolset has a higher switching frequency for 5th gen than 3rd gen, what does this answer mean?

>>The 5th generation can be used for buck topologies.
>>The 3rd generation is not very suitable due to the high switching frequency.

Thanks

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Pablo_EG
Moderator
Moderator 250 sign-ins 250 replies posted 25 likes received
Moderator

Hello Fujioka-san,

Q: Can CoolSET be used as a non-isolated AC/DC buck chopper as shown in the attached Figure?
A: Yes, CoolSET can be used for the buck topology, as shown in the image.

Q: Also, I think Coolset has a higher switching frequency for 5th gen than 3rd gen, what does this answer mean?
A: Please ignore my comment regarding the frequency. If you want to know about this comment more in detail, please contact Infineon Sales.

If you want to know more about using CoolSET for buck topologies and which generation to use, please contact Infineon Sales.

Best regards,
Pablo

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NXTY_Fujioka
Level 2
First solution authored 5 replies posted 10 sign-ins
Level 2

Hi Pablo-san,

Thank you for your answer.

There's just one more thing.
The absolute maximum ratings for the CS pin of CoolSET are specified, for example, the CS withstand voltage of +3.6Vmax for ICE5GR2280AG and +5.5V for ICE3AR0680JZ.

So, for example, am I right in thinking that it cannot be used for a buck converter with 24VDC output?
Thanks

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Pablo_EG
Moderator
Moderator 250 sign-ins 250 replies posted 25 likes received
Moderator

Hello Fujioka-san,

Could you explain the reasoning behind your statement?

V_cs will change depending on the current flowing through the device.
So Vcs_max will limit the peak of the current.
If the output of the buck is 24V, as long as the Id is lower than Vcs_max/Rsense, it should be possible.

Please correct me if I misunderstood your question.

Best regards,
Pablo

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NXTY_Fujioka
Level 2
First solution authored 5 replies posted 10 sign-ins
Level 2

Hi Pablo-san,

When using CoolSET as a non-isolated AC/DC Buck Converter, I think that the CS pin voltage will be a square wave between 0V and Vin(DC) as shown in the figure below.
I believe that when a typical AC input is applied, Vin(DC) will be much higher than the absolute maximum rating of the CS pin.
Is this kind of usage a problem?

NXTY_Fujioka_0-1654861035440.png

 

Thanks

 

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Pablo_EG
Moderator
Moderator 250 sign-ins 250 replies posted 25 likes received
Moderator

Hello Fujioka-san,

In the case of a buck converter, the GND pin of the device will not be connected to the GND line.
It will be connected to the Vcs point in your image.
Therefore, the CS pin will only experience the V_shunt voltage.
For further questions regarding this application, please contact Infineon Sales.

Best regards,
Pablo

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