LM5176: The LM5176 inductance is hot

hongwei duan

Part Number: LM5176
Other Parts Discussed in Thread: LM5175

Hello, I have a project using LM5176. The input voltage is 11V-25V, the output is 12V, the switching frequency is set to 100KHZ, the subsampling resistance is 3mΩ, the output sampling resistance is 3mΩ, the conversion inductance is 3uH, and the DC impedance of the inductance is 3mΩ. It is found that the temperature of the inductance is about 50-60℃ when the inductance is unloaded. I would like to ask how to improve the temperature of the inductor and output capacitor.

over 1 year ago

0 Stefan Schauer over 1 year ago

TI__Guru 58661 points

Hi Hongwei,

thank you for using the E2E forum.

The LM5176 does not support DCM like the LM5175.
With the used CCM mode therefore the losses are higher in light or now load operation. If this would be an important requirement you might need to change to the LM5175.

Both devices are Pin compatible but require some different external components, e.g RT resistor or for LM5175: It is recommended to add 7.8V or 8.2V Zener diodes from SWx to BOOTx to stay below the abs max rating of 8.5V (layout dependent)

Best regards,

Stefan

0 hongwei duan over 1 year ago in reply to Stefan Schauer

Intellectual 450 points

Hello, finally I increased the switching frequency, and finally the temperature is not so hot.

0 Stefan Schauer over 1 year ago in reply to hongwei duan

TI__Guru 58661 points

Hi Hongwei,

thanks for letting me know.

Best regards,

Stefan

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LM5176: The LM5176 inductance is hot