LM43600: LM43600PWPR power output on the WEbench and the simulation is 5Vdc but on the PCB its only 1.3Vdc

mohammad nadeemuddin

Part Number: LM43600

Hi,

I am using the below schematic on the PCB for a 5VDC out.

part number used: LM43600PWPR.

i used the same schematic in the last version of the board and even check the part number on the board, the old board works well but the new one doesn't work even though the parts are same, schematic is same, and layout is same.'

can anyone help me?

11 months ago

0 Youhao Xi 11 months ago

TI__Guru 72025 points

Hi Mohammad,

Thank you for designing with LM43600, and sorry to hear your problem. Can you monitor EN, VCC and FB voltages and let me know what are the reading? Can you change to a new IC and see if the current IC is damages somehow?

Best Regards,

Youhao

0 mohammad nadeemuddin 11 months ago in reply to Youhao Xi

Prodigy 20 points

i did change the IC,EN is high, VCC is using a 2.2Uf and i see a periodic sawtooth with a 3.3vdc. i will try to get some scope readings.

thank you

0 mohammad nadeemuddin 11 months ago in reply to Youhao Xi

Prodigy 20 points

hi Youhao,

here are the signals you requested.

+1 Youhao Xi 11 months ago in reply to mohammad nadeemuddin

TI__Guru 72025 points

Hi Mohammad,

Thank you for the info. Sorry I missed it in my previous review. You need to delete C145 or reconnect it after the inductor. Otherwise it will create a surge current each time the high side is switching and interrupt the operation.

Hope this resolves the issue.

Best Regards,

Youhao

0 mohammad nadeemuddin 11 months ago in reply to Youhao Xi

Prodigy 20 points

hi Youhao,

Thank you, that did resolve the issue.

Power management

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LM43600: LM43600PWPR power output on the WEbench and the simulation is 5Vdc but on the PCB its only 1.3Vdc