LM61480: Dual Voltage Power Supply using LM61480

Md RASOOL

Part Number: LM61480

Greetings Team,

I have a use case that needs 5 and 3.3 volts on the board to work. I have used the LM61480 design from Webench designer and implemented it. The issue is that I can't seem to operate them simultaneously. I have had good results when only one of them is populated on the board. But when I use them concurrently 3.3V IC shorts internally (inductor pin shorts to GND as soon as the power supply is switched on). Looking forward to your answers.

6 months ago

0 Jimmy Hua 6 months ago

TI__Guru 50120 points

Hello,

Please provide a schematic for review.

By simultaneous, I am assuming you have two separate LM61480 circuits (one circuit for 5V and one circuit for 3.3V) powered from the same input supply.

Regards,

Jimmy

0 Md RASOOL 6 months ago

Prodigy 20 points

Thanks for replying Jimmy. Yes. The microcontroller is connected to 3.3V and when needed sends a High signal to 5V buck's EN pin.

0 Md RASOOL 6 months ago in reply to Md RASOOL

Prodigy 20 points

Please check your email. I have shared the schematics to you.

0 Md RASOOL 6 months ago in reply to Jimmy Hua

Prodigy 20 points

I just wanted to include that the input voltage is 12.6V, equivalent to the peak voltage of a 3S Li-ion pack.

0 Jimmy Hua 6 months ago in reply to Md RASOOL

TI__Guru 50120 points

Hello,

it looks like you sent a separate offline email. As such I’ll close this thread and continue support offline so as to consolidate the troubleshooting.

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LM61480: Dual Voltage Power Supply using LM61480