TPS61175: Can flyback usage support an isolated 48V output?

K.Shidara

Expert 3225 points

Part Number: TPS61175

Team

My customer is looking for a 14V input, isolated 48V output (max 15.4W) boost converter.

There is TPS61175PWPR (~ 18V input, ~ 40V output) and it was written that the flyback can be supported

in datasheet.

Even if it is IC of rated output 40V, if it is flyback method,

is it possible to make 48V output on the secondary side of the transformer with TPS61175?

Thanks

Best regards,

Shidara

over 6 years ago

0 Youhao Xi over 6 years ago

TI__Guru* 78070 points

Hi K.

The engineering supporting this device is current ooo on holidays until after May 3rd. I think it is possible but the max voltage stress on the SW should be less than 40V. You need to consider the min input voltage to select the max duty cycle and transformer turns ratio, and assess the max SW stress under the max input voltage. Please refer to the tool at the following link to help you.

www.ti.com/.../flybuck-flyback-design-calc

Thanks,
Youhao

0 Helen chen over 6 years ago

TI__Mastermind 40080 points

Hi-Shidara,

Youhao is right. what is the input voltage range?

0 K.Shidara over 6 years ago in reply to Helen chen

TI__Expert 3225 points

Hi Helen-san

Thank you very much for the advice.

Let me double check the input condition.

Thanks

Best regards,

Shidara

0 Helen chen over 6 years ago in reply to K.Shidara

TI__Mastermind 40080 points

Dear Sir,
Any feedback on the input condition?

0 K.Shidara over 6 years ago in reply to Helen chen

TI__Expert 3225 points

Hi Helen

Thanks for your reminder.

Input condition is 14V±2V.

Thanks

Best regards,

Shidara

0 Helen chen over 6 years ago in reply to K.Shidara

TI__Mastermind 40080 points

Hi Shidara,
The Vin variation range is not big. So a flyback topology is OK for this design. you can set Np:Ns=2:5 to achieve the target. And you can add a RCD snubber at the primary side to supress the spike.

0 K.Shidara over 6 years ago in reply to Helen chen

TI__Expert 3225 points

Hi Helen-san

Thank you so much for your advice.

Understood.

Thanks

Best regards,

Shidara

0 Helen chen over 6 years ago in reply to K.Shidara

TI__Mastermind 40080 points

You're welcome! Good Luck!

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TPS61175: Can flyback usage support an isolated 48V output?