LM5060: LM5060MM/NOPB

Fero Prokes

Part Number: LM5060
Other Parts Discussed in Thread: LM5069, CSD19536KTT

Good morning to E2E,

I would like to ask you for some help. I have new project for our customer, where high capacity (15 000uF) load is switched to 48VDC. The application is an Power Controller Board 48VDC / 1kW. To switch on the power line, i'm using the LM5060 with N-FET SUM70040E. The problem is, that the FET burns after switch on, and also LM5060 is not functional anymore.

Schematic is default from the datasheet, and values are calculated using the LM5060 Design_Calculator_REV_C.xlsx

Can You plese give me some advice, whats wrong ?

over 5 years ago

0 Fero Prokes over 5 years ago

Prodigy 50 points

Here is the schematics

0 Rakesh over 5 years ago in reply to Fero Prokes

TI__Guru** 105531 points

Hi Fero,

Welcome to E2E and thanks for reaching out.

15mF is huge on 48V rail. What is the value of inrush current you set for ? Do you have any additional load during startup apart from 15mF ? Can you share the startup test waveforms Vin, Vout, inrush current and GATE voltage.

For this kind of application, controller with FET SOA protection would be ideal such as LM5069.

Best Regards, Rakesh

0 Fero Prokes over 5 years ago in reply to Rakesh

Prodigy 50 points

Dear Rakesh,

I have no functional LM5060 left. Therefore i can not provide any waveforms, from the functional prototype. But i will change the board and switch to using LM5069. SOA protection is good improvement.

Do You have any recommendation regarding LM5069 with high capacity load ? I ordered the dev-kit right now and i will start from the dev-kit schematics.

In first step i will change components values using LM5069 Design Calculator (Rev. D)

And hopefully it will work.

0 Rakesh over 5 years ago in reply to Fero Prokes

TI__Guru** 105531 points

Hi Fero,

Nice to hear that you switched to LM5069. To start, please send me filled-up design sheet for review. The design sheet has links to the video tutorials to assist in the design. Please consider PSMN4R8-100BSE or CSD19536KTT MOSFET for the design.

Best Regards, Rakesh

0 Fero Prokes over 5 years ago in reply to Rakesh

Prodigy 50 points

Hi Rakesh,

Please find the filled XLS in the attached file. Based on this experience, i reduced CAPs on the output to half of original value. I will add an 11°C/W heat sink to the MOS-FET. And if there is enough of space, i will add second N-FEN. LM5069_Design_Calculator_REV_C-CSD19536KTT.xlsx

0 Rakesh over 5 years ago in reply to Fero Prokes

TI__Guru** 105531 points

Hi Fero,

Instead of heat sink, I suggest to add another MOSFET in parallel. Use dvdt circuit to support startup and resistor divider across Rsense to fine tune the current limit.

I have attached the modified design sheet for your reference.

mod_LM5069_Design_Calculator_REV_C-CSD19536KTT.xlsx

Best Regards, Rakesh

0 Fero Prokes over 5 years ago in reply to Rakesh

Prodigy 50 points

Hi Rakesh,

New modul with LM5059 has solved all issues. Thank You for help!

Best regards,

Fero

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LM5060: LM5060MM/NOPB