LM5045: Seeking Recommendation for PWM Controller for 300W Isolated Full-Bridge DC-DC Converter for EV Application

Yashaswini M N

Part Number: LM5045
Other Parts Discussed in Thread: UCC2808A-2Q1, UCC2808A-1Q1, LM25037-Q1, LM25037

Tool/software:

Hi,

I’m currently working on the design of a 300W isolated full-bridge converter electric bike application, with the following specifications:

Input Voltage: 60–75 VDC
Output Voltage: 12 VDC
Output Current: 25 A
Topology: Full-Bridge Isolated
Switching Frequency: 100 kHz
Isolation Requirement: ≥ 3 kV
Target Efficiency: ≥ 92%

While exploring available options, I came across the LM5045 full-bridge PWM controller and wanted to check with you:

Would LM5045 be a suitable choice for this application, or would you recommend another controller better suited for this power level and EV use case?
Could you please share any available reference designs, application notes, or design guidelines for isolated full-bridge DC-DC converters in this voltage and power range?
Additionally, if possible, could you guide me on transformer design recommendations (core selection, turns calculation, winding arrangement, and auxiliary bias winding implementation) compatible with your recommended controller?

I would really appreciate your advice and any reference material you could share for this design.

Thank you very much in advance for your support!

2 months ago

0 Hong Huang 2 months ago

TI__Guru 73905 points

Hi,

Do you need automotive graded devices?

0 Yashaswini M N 2 months ago in reply to Hong Huang

Prodigy 75 points

Hello,

Yes, it would be good to have automotive-graded devices.
If they are not available, standard ones are also acceptable.

0 Hong Huang 2 months ago in reply to Yashaswini M N

TI__Guru 73905 points

Hi,

1. LM5045 does not have automotive graded parts. Also we do not have a part like LM5045 with automotive grade. We have two parts LM25037-Q1 and UCC2808A-1Q1, or UCC2808A-2Q1, but these need to have external bridge drivers to make full bridge converter.

2. You can look at LM5045 EVM or LM25037 EVM as reference design.

3. We do not have good experience on transformer design as we usually use our transformer vendors to make transformer design and to get the transformers. You can review the below for transformer design guide.

https://www.ti.com/lit/ml/slup126/slup126.pdf

https://www.ti.com/seclit/ml/slup132/slup132.pdf?ts=1751486821516&ref_url=https%253A%252F%252Fwww.ti.com%252Fabout-ti%252Fevents%252Fpower-supply-design-seminar%252Fpsds-library.html%253FkeyMatch%253Dmagnetic+design+handbook%2526tisearch%253Duniversal_search

0 Yashaswini M N 2 months ago in reply to Hong Huang

Prodigy 75 points

Hi,

We have finalized the LM5045 controller. Please provide a 240W isolated DC-DC converter reference design using LM5045, including transformer specifications.