UCC28C42-Q1: Is isolated power supply required for the system getting power directly from alternator?

Ajmal T

Part Number: UCC28C42-Q1
Other Parts Discussed in Thread: UCC28C42

Hi,

I have to design a power supply for a lawn mower system, which is taking power from alternator directly and converting it to the required DC power rails. There is no battery in the system.

Should I consider isolated power supply at the first power conversion stage?

When isolation is required in automotive power supply design?

Regards,

Ajmal T

over 4 years ago

0 Teng Feng over 4 years ago

TI__Genius 13660 points

Hi Ajma,

I assume that you are using a fly-back topology, which is an isolated converter.

In this design, you can an auxiliary winding to supply bias voltage to the UCC28C42, so no extra supply power is required.

If you want to use an extra supply power instead of auxiliary winding, yes it should be isolated with secondary side.

Regards,

Teng

0 Ajmal T over 4 years ago in reply to Teng Feng

Intellectual 420 points

Hi Teng,

Thanks for the reply.

My doubt is whether this system (taking power from alternator directly and converting it to the required DC power rails) required Isolation or not? Are you recommending it?

If isolation is not required, my plan is to design the system with another topology to avoid the use of customized transformer.

Regards,

Ajmal

0 Teng Feng over 4 years ago in reply to Ajmal T

TI__Genius 13660 points

Hi Ajmal,

My understanding is that you are asking the first stage to convert AC power (from alternator) to DC power? It doesn't request an isolation.

But if the terminal system request an isolation with first stage, you should use a isolated DC/DC converter.

Regards,

Teng

0 Ajmal T over 4 years ago in reply to Teng Feng

Intellectual 420 points

Thanks for the inputs

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UCC28C42-Q1: Is isolated power supply required for the system getting power directly from alternator?