Switching/Linear Hybrid Lab Bench Power Supply, Recommended AC-DC Controller IC ?

Nabil M

Hi,

I'm thinking of designing a lab bench AC-DC power supply with dual polarity variable outputs. I want to keep this challenging so I'm going for 1.25V to 15V (1A) and -1.25V to -15V (-1A), and I want to minimize BOM cost while maintain medium power density (30W). My thought was using a flyback configuration to step down the line voltage To a +/-18V with a center tapped flyback transformer. I then want to cascade a positive and negative adjustable LDO rated for 1A for each output of the flyback.

Sort of like a hybrid between switch mode and linear. I was planning to use one of the offline AC-DC converters for the flyback converter.

Do you have a recommended part and or reference design ? What are your thoughts to this approach.

Thanks,

Nabil

over 8 years ago

0 Yunsheng Qu over 8 years ago

TI__Genius 9790 points

hi, Nabil

Thanks for your interest in TI here. I've contacted the appropriate product group. You should hear from them soon.

BR,
Yunsheng

0 Benjamin Lough over 8 years ago

TI__Mastermind 27105 points

Hi Nabil,

PMP7263 is similar to the flyback design you have in mind. http://www.ti.com/tool/PMP7263. This approach looks reasonable but be aware that the LDO's will have poor efficiency when configured for +/- 1.25V.

As the output power is split equally between your two rails, you might want to consider using weighted feedback. This would allow you to regulate both outputs using 1 feedback network. Take a look at this article: www.eetimes.com/author.asp

Best Regards,
Ben Lough

0 Nabil M over 8 years ago in reply to Benjamin Lough

TI__Intellectual 1840 points

Thanks a lot Ben.

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Switching/Linear Hybrid Lab Bench Power Supply, Recommended AC-DC Controller IC ?