LM5160A: LM5160A

Shachar Armon

Prodigy 230 points

Part Number: LM5160A
Other Parts Discussed in Thread: LM5160

Tool/software:

Hi,

We need to have in the system +5.5Vdc and -5.5Vdc,

we would like to implement this by DCDC Flyback,

we considering use LM5160 similar to typical application in the datasheet implementation

The only difference is that we need to negative voltage,

I would like to ask the following things:

1. can you better explain what make this specific DCDC best fit for flyback?

2. for the negative secondary voltage, the option are according to my understanding:

2.1 transformer winding

2.2 different circuit connection of the secondary side (attached pic)

3. can it be implemented with Inductor array, SRF0703-220M or similar approach?

Shachar

2 months ago

0 David Baba 2 months ago

TI__Mastermind 40040 points

Hello Armon,

Please see responses below.

1. Fly buck does have the benefit for being able to clamp the Switch node to the input voltage and in many cases is a simpler approach to implementation. see link below for more details.

https://www.ti.com/document-viewer/lit/html/SSZT959

2. As in flyback, dot polarities are opposite, and anode connects to output as you have shown above.

3. the inductor looks ok; I could not find the leakage specification. Suggest keeping leakage inductance to about 1% to keep the currents from swinging negative excessively during the off period. The higher the leakage the greater the swing. Also watch out for inductor currents during the conduction period, ensuring that the peak currents do not saturate the inductor. 1.6A, seems reasonable to me. but will come down to your load currents.

please refer to the spreadsheet below to estimate your peak currents etc.

https://www.ti.com/tool/download/FLYBUCK-FLYBACK-DESIGN-CALC

Also refer to this paper for a comprehensive guide.

https://www.ti.com/lit/an/snva674c/snva674c.pdf?ts=1752501148465&ref_url=https%253A%252F%252Fwww.google.com%252F

Hope this helps.

David.

Power management

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LM5160A: LM5160A