TPS54428 Question

Martin Risso

I need to monitor load current. If I add a current sense resistor, in the 0.020 to 0.030 range after the output capacitor and then take the voltage feedback divider top from the load side of the current sense resistor, does that have the potential to cause any loop stability problems?

Marty

over 9 years ago

0 JohnTucker over 9 years ago

TI__Guru**** 191445 points

I have never tried that with any of these devices. On one hand 0.020 ohm is not very much resistance. To play it safe, you cold consider using the inductor DCR as the sensing resistor, but adding that much additional series resistance should not be a problem.

0 Nick Chen over 9 years ago

TI__Prodigy 575 points

Could you draw us a figure? I'm not sure I understood your method 100%...

0 Martin Risso over 9 years ago in reply to Nick Chen

Intellectual 470 points

Hi Nick

I srew the schematic and inserted it as a PDF. Does it come through?

Marty

CURRENT_SENSE.pdf

0 Nick Chen over 9 years ago in reply to Martin Risso

TI__Prodigy 575 points

Hi, Martin,

I haven't tried it before, but I think it's plausible. just check not to exceed the maximum power consumption on the 0.033 resistor since the load current will pass through it.

Power management

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TPS54428 Question