LMK05318B-Q1: Damage Reason

Hi Yuning,

Could you specify what pins are short? In the normal operating condition, what are the input voltage to the IC and the current reading?

Also, is the IC supplied with any input signal during power off stage? The device does not have fail-safe so if the voltage and current input present during power off stage, it could cause damage to the IC.

-Riley

LMK05318B-Q1.ziphi Riley,

        Background: This IC had a problem during the experiment, and we took it back for analysis. When it is not powered on, there is a short circuit in the power rail where the 4Pin is located, and the resistance value of this power rail on the mainboard is about 1ohm. When disassembling this IC, the circuit impedance returns to normal, and there is a short circuit inside the 4Pin of the IC chip. Please be informed.

PS: The IC waveform is measured in normal operation, please help confirm whether the waveform is normal, thank you.

Hi Yuming,

Can you please share the schematic used for the LMK05318B-Q1?

Regards,

Jennifer

LMK05318B-Q.pdf

hi Jennfier,

        Here is our SCH, Please check.

HI  Jennifer，

          I want to know Who supplies power to the SDA and SCL ports inside the IC?

          Thanks

Power off.zip

HI  Jennifer，

       When the IC was powered off, some abnormal VDIG waveform was found. Please help to confirm whether it will affect the IC and eventually lead to internal short circuit of the IC.

    Thanks

Hi Yuming,

As long as the Absolute Maximum Ratings are not exceeded, I do not see concern with the device becoming damaging.

However, I probed on the LMK05318BEVM between VDD_DIG and GND when the device is powered OFF and there is no short. Your short circuit behavior is not expected. Please try replacing your current device under test with a new part and let me know if the problem continues with the new part.

Regards,

Jennifer