THVD8000EVM: DC supply for THVD8000 signal chain

Wenting Wu

Part Number: THVD8000EVM
Other Parts Discussed in Thread: THVD8000

Tool/software:

Hello expert,

To follow my previous questions.

If 36V line is DC power supply not AC power supply, can the tranfermer still be used? are there difference on design for AC supply and DC supply?

Refer to the following reference design, there is a transformer used. If the DC supply used, can we still follow it?

Do we need the inductor for DC supply?

https://www.ti.com/tool/PLC010935BP

Best regards,

Wenting

28 days ago

+1 Parker Dodson 28 days ago

TI__Guru 52062 points

Wenting,

When using a transformer you don't use the normal coupling network.

The guide that ref. design is based on is this: https://www.ti.com/lit/an/slla590/slla590.pdf?ts=1693491025500&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTHVD8000

The transformer is used to inject data onto a power bus.

AC/DC doesn't matter - the HV coupling network (transformer and capacitor) - allow high frequency data to pass but block DC and low frequency AC signals from going back into the communication node. HV implementations don't create a shared bus - it injects data onto a power bus. It is a small but critical difference.

Best,

Parker Dodson

0 Wenting Wu 25 days ago in reply to Parker Dodson

TI__Intellectual 2335 points

Hello Paker,

We will follow the reference design to try. https://www.ti.com/tool/PLC010935BP Could you help to view the specification of transformer?

Best regards,

Wenting EBF1-6T-G035082.pdf

0 Parker Dodson 25 days ago in reply to Wenting Wu

TI__Guru 52062 points

Hi Wenting,

That transformer looks fine and has low insertion loss and return loss over the range of the THVD8000 modulation frequency - just remember that you need to have a capacitor (the reference design uses two which is fine) between the transformer and the main bus - that will prevent the DC current from damaging the transformer and/or making communication impossible - the THVD8000 signal will be able to pass through the capacitor - but the DC signal won't.

Best,

Parker Dodson

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THVD8000EVM: DC supply for THVD8000 signal chain