TPSM53602: negative output current behavior

HI

it can't output negative current as it only work at PFM mode. When device is working, the current may go to negative due to ZS order detection have some variation. you can also take a close look at inductor current waveform at stable statue with 2us-5us/div, currently the waveform sample rate is too low to catch the detailed waveform in one switching cycle time.

Thanks

Hi Daniel,

Thank you for  detailed explanation.

We capture waveform with 5us/div again.

Negative current is observed due to affect of the evaluation environments,
and TPS53602 does not output negative current actually.
Is it correct ?

TPSM53602 Output Current_2.pdf

HI

can I know which point you test the waveform, it looks like the capacitor current ripple or output current ripple, do you test the inductor current in below point?

Hi Daniel,

Thank you for reply!

Test point is described in attached file.

Test points is behind TPSM53602's output capacitor.
However there are some capacitors in circuit powerd from TPSM53602.
Is the behavior of current ripple due to the influence of these capacitors ?

TPSM53602 Current Test Point.pdf

Hi

based on your test result, it is output current ripple which is proportion to output voltage ripple. it is influenced by these capacitor. normally, we say negative current means inductor current go to negative or average of output current become negative.

Thanks

Daniel Li

Hi Daniel,

Thank you for detailed explanation !