Using SMPS near DWM1001 Module

Hi,

I am trying to run DWM1001 with an SMPS of 5V 1A output. I am currently using IRM-05-5 from MeanWell.https://www.mouser.in/datasheet/2/260/r1936_3-1109422.pdf

What about the effect of EMI if I place the SMPS near DWM1001. What is the safe distance between SMPS and DWM. What are the PCB Design rules if I would like to place SMPS near DWM1001.

Any help around the EMI/EMC effects due to power electronics would be great .

Thanks,
Nav

Hi Nav,
You can’t power the DWM1001 from 5 V as it requires a 3.3 V supply. Also, the DW1000 IC can be sensitive to power transients when entering transmit and receive modes, so you should select a DCDC with fast transient response. The part you’re using from MeanWell seems to be quite a heavy duty part, almost like an AC adapter and I’m not sure how suitable it is. But as it outputs 5 V, you’re going to need a regulator to take that down to 3.3 V anyway. You could use Torex XC9258B33, which we have validated for use with DWM1001. It’s listed on the DW1000 datasheet as a recommended part also.
For layout guidelines regarding EMI, it’s always important to follow the vendors specific guidelines. Usually you need to ensure power inductor and capacitor components are kept as close as possible to the regulator IC, use wide PCB traces, etc. to ensure current return loops are minimised.

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Hi S_Carrol,

Thanks for the reply.

I am using DC/DC between AC SMPS and DWM1001. Currently I am using RT8509. I am keeping capacitors and inductors close to regulator.
I have provided sufficient space for Antenna and created a safe isolation area around Antenna from ground/Metal.
If I keep SMPS and the DWM1001 on the Top layer, 30mm apart will have any effect on radio?
any suggestions around this would be great help.

Thanks,
Nav

Hi Nav,

Actually, when we evaluated the Richtek RT8509, the transient response wasn’t fast enough and we occasionally saw packet errors in our UWB link. So I would recommend you that you change to the Torex XC9258, which we have seen shows no issues.

Once your PCB layout of the DCDC is correct, then you don’t really need to worry too much about the proximity. It makes sense not to place it close to the antenna. 30 mm clearance is certainly plenty.

Thanks S_Carrol. Appreciate your help.

Regards,
Nav