LMR36503-Q1: Short current spikes over the spec limit

Hi Wen,

The part can handle a DC load current of 300mA but the current limit includes the AC inductor ripple current and the current limit specs are show below: 

Ben

Thank you!

Here are some current waveforms, are they okay to use with LMR36503-Q1?

Thank you!

Hi Wen,

Can you provide me more details of the conditions when you took these scope photos? How are you measuring the current? Are you using a current probe? 

Ben

Hi Ben,

Both captures are using current probe. For the one with 2 traces, 1 mV equals 1 mA, the bottom trace zooms into the top trace. Peak is 354 mA, Time scales are 5 ms per division and 200 usec per division. The bottom dotted line is at 300 mA.

For the other capture, it's already in mA scale, it's taken with different condition, so the current is different.

Thank you!

Hi Wen,

At what event did you capture these plots? For example, a short circuit event?

Ben

Hi Ben,

The capture is during power up of device, it rarely happens during normal operation.

Wen

Hi Wen,

How much capacitance does the output have?

Ben

Hi Ben,

Just to clarify, the captures were with a different DCDC converter and the waveforms are part of device initialization (not a power up sequence). I have not powered my device with a LMR36503-Q1 yet. We will use what the data sheet recommends.

Wen