LM2738: Schottky diode D1 need

Power D

Prodigy 20 points

Part Number: LM2738

Dear all,

I use this design for my circuit, but I realized that when I removed D1, my board still work well.

Can you confirm that D1 is necessary or not? since I think this diode is essential for a buck topology.

Thank you,

Power Dao

over 2 years ago

+1 Zixu Wang over 2 years ago

TI__Expert 8100 points

Hi Power,

Could you please share your waveforms(SW voltage, inductor current, Vout, etc) in application?

And is the shown schematic applied for your application?

BRs

Zixu

+1 Nancy Zhang over 2 years ago in reply to Zixu Wang

TI__Mastermind 47020 points

Hi Power,

You can not remove the D1 since it is a freewheeling diode for Buck converter. The main function of that diode is to freewheeling the energy stored within the inductor by continuous load current. This is essential to protect the IC, otherwise the IC and internal FET are likely damaged even if it will work without that diode. Please refer to the link as below.

Freewheeling Diode or Flyback Diode : Circuit, Working & Its Applications (watelectronics.com)

Hope this helps,

Thanks,

Nancy

Power management

Power management forum

LM2738: Schottky diode D1 need