MP4562 : Noise on the DC/DC output

DC-DC Power Converters
1

Hello,

I am using an MP4562 on a PCB to convert 48 V input to 19 V output (position 2). However, I am observing significant noise on the output at around 1 MHz. The switching frequency is set to 1 MHz, but there appears to be considerable ringing at each switching event plus the triangular signal amplitude seems too high.

This noise is affecting the proper operation of my system, and it increases with the load current.

I have attached the schematic, PCB layout, and oscilloscope measurements. For the measurements, I powered the board using a laboratory power supply and probed the output. The output is connected to a 62 ohms load here.

I am unsure whether the selected components (especially the diode => PMEG10020ELRX) are appropriate, and I would appreciate any advice on how to improve the output signal quality and reduce the ringing.

Thank you in advance for your help.

PS : the oscilloscope probe is set on AC.

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IMG_20260504_115921
IMG_20260504_1159211920×2560 261 KB

Capture schematic
Capture schematic1456×910 106 KB

2

Hi @julien.lambert ,

I believe the biggest source of noise could be coming from your long wires. What’s your application, and does it require the long wires? If possible, can you try using shorter wires? We can first start with shortening the ground loop of your probe and measuring across C6, then across the 62ohms load (try using a tip & barrel method as shown below):

image
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Can you also share your expected load current?

Thanks,
Rubas