LM3488: The IC is literally catching fire

Anish Bekal

Part Number: LM3488

Hi,

I am using a LM3488 ic for converting from 24V to 5V in a motor driver circuit. The current limit of external power supply of 24V is set at 2A. The 24V is separately connected to motor driver also. Under some condition whethe motor draws large current the External power supply reaches current limit and drops to 4V. Under this condition for unknown reason. The LM3488 ic literally catches fire.

The circuit diagram of the LM3488 converter is exactly same as in the datasheet (except Rsn = 0.15 ohms) . The burnt image is shown below.

over 1 year ago

0 Haroon Wardak over 1 year ago

TI__Genius 10385 points

Hi Anish,

Thank you for using E2E forums, Do you have a better and simpler schematics for your design so that I could look into this?

BR,

Haroon

0 Anish Bekal over 1 year ago in reply to Haroon Wardak

Prodigy 40 points

Here is the PDF of the Schematic.BLDC Motor driver.pdf

0 Haroon Wardak over 1 year ago in reply to Anish Bekal

TI__Genius 10385 points

Hi Anish,

Please allow me some time to get back to you on this.

BR,

Haroon

0 Haroon Wardak over 1 year ago in reply to Anish Bekal

TI__Genius 10385 points

Hi Anish,

With your sense resistor you have set the current limit to somewhere between 0.68 - 0.25 A, and when you input supply voltage goes to 4V your input current will be around 1.7A, so your circuit would go in over current triggering. However, regarding why the IC got damaged, when you connect the motor on the same supply line as the LM3488 it could be that the signal coming from the motor damaged the IC, I cannot say. Do you have any sort of protection in that regards? like a protection that makes sure there is no current coming out of the motor into the LM3488?

BR,

Haroon

0 Haroon Wardak over 1 year ago in reply to Haroon Wardak

TI__Genius 10385 points

Hi Anish,

Since I got no replies from you I will assume this issue is resolved and I will close this thread.

BR,

Haroon

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LM3488: The IC is literally catching fire