LMR23610: Not functioning as expected

Vincent S.

Part Number: LMR23610

I have implemented this simple switcher regulator circuit in a project with the output set to 5V.

Upon power on, the output voltage was about 2V with Vcc (pin 3) measured at about 3.7V and Vfb around 0.5V. The feedback resistors are Rtop: 88.7k and Rbot: 22.1k.

For your reference, the schematic, layout and the recommended Web Bench solution are attached to this email.

Thanks.

over 8 years ago

0 Arief Hernadi over 8 years ago

TI__Mastermind 23845 points

Hi,

Your feedback voltage Vfb does not seem to be correct. Do you have schematic/layout of your design?
Do you also have the switch waveform on the oscilloscope?

Thanks

-Arief

0 Vincent S. over 8 years ago

Prodigy 20 points

Yellow: 24V input, Blue: Vout

Yellow: SW node response

Blue: VCC response

Hi David, Pete and Arief,

I would like to add some waveforms captured on a scope.

0 Arief Hernadi over 8 years ago in reply to Vincent S.

TI__Mastermind 23845 points

Hi,

It seems that you reg 5V trace is right underneath a switch node, i would cut this trace and routed the connection to top feedback resistor away (RFBT). Conneted away from inductor.

Thanks

-Arief

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LMR23610: Not functioning as expected