LMR16030: LMR16030, Cff capacitance and output ripple problem

Hi,

Could you please tell us what are all 4 waveform channels? Could you please probe SW node and zoom it in for the both conditions? Thanks.

turquoise is the input of DC/DC,

green is the voltage of output  5V,

pink is the ripple(Vp-p) of output 5V,

yellow is the load current of output 5V.The waveform is connected to electronic loading 1A and 900mA.

Can I get your email? I can send you the waveform of each loading with 470pF Vs 12pF.

My email : rctan@computime.com

Hi,

OK, I see, could you please probe SW node and zoom it in for the both conditions? It might cause loop unstable using different Cff.

I can paste pictures on here and I have no your email . Can you send an email to my email : rctan@computime.com

I will send you the waveform of each loading with 470pF Vs 12pF.

Mybe could your down load the document from the baidu pan : link ,code is n6we.

Hi,

I recommend that you upload the files in the post so that other people might have the same question can search for it. Thanks.

1, 5V without loading, then add 1A loading(the output voltage ripple Vp-p with 12pF is better than 470pF)

2、470pF,18VAC input, Electron Loading 0~2A, input VTP94 OK, output 5V OK. the output voltage ripple Vp-p<320mV

3,change to 12pF

also 18VAC in ,Electron Loading 0~2A, input VTP94 OK, output 5V OK.And the output voltage ripple Vp-p<50mV

Hi,

Could you please Zoom Vout in and also probe SW node, it's helpful to check if the loop is unstable. Thanks.