LM3150: LM3150:

Ingo Grothe

Prodigy 10 points

Part Number: LM3150

Tool/software:

Hi there,

I use the LM 3150 to step down from 26V to 21.3 .

Input should be max. 2.3 A.

Its to charge a LiFePO Battery.

When i connect first the input at 26 V then the Battery its working.

If the Battery is connected first it will destroy the controller evry second or thirt time.

Can you help me to save the chip?

Its very urgent.

Thank you

Ingo

2 months ago

0 ARPITA NATH 2 months ago

TI__Expert 8342 points

Hi Ingo,

Please share the schematic and filled-in excel tool according to your conditions.

LM315XQUICK-CALC Calculation tool | TI.com

What is the pre-charge of the battery when you first connect the battery??

Regards
Arpita

0 ARPITA NATH 2 months ago in reply to ARPITA NATH

TI__Expert 8342 points

Hi Ingo,

When you connect the battery first [having some pre-biased voltage, not fully discharged] when the input is disconnected, current will flow through the body diode of the high-side MOSFET of the buck converter and charge the input capacitor. This will cause a large spike of current and can possibly damage the MOSFET.
You can try putting diode in series with the output of the LM3150 to prevent current from the battery from flowing to the input.

Regards

Arpita

0 Ingo Grothe 2 months ago in reply to ARPITA NATH

Prodigy 10 points

Thank you for the soon reply

I thought about this but it will degree the efficiency.

Maybe there is another way to get rid of the Spike ?

Regards

Ingo

0 Ingo Grothe 2 months ago in reply to Ingo Grothe

Prodigy 10 points

I forgot to tell you that the Mosfet is not damaged.

Its always the LM 3150.

0 ARPITA NATH 2 months ago in reply to ARPITA NATH

TI__Expert 8342 points

I will check in details and get back to you. How are EN and SS connected?

Please share the schematic and filled-in excel tool according to your conditions.

LM315XQUICK-CALC Calculation tool | TI.com

What is the pre-charge of the battery when you first connect the battery??

Please provide the above information to understand your application and the issue

Regards

Arpita

0 ARPITA NATH 2 months ago in reply to ARPITA NATH

TI__Expert 8342 points

Hi Ingo,

Did you get a chance to check the above points? Also, please share schematic and filled excel tool as stated earlier.

Regards

Arpita

Power management

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LM3150: LM3150: