RE: Questions on nRF54LM20-CAAA (CSP61) hardware design

JONATHAN LL — Tue, 23 Jun 2026 14:40:11 GMT

Hello,

[quote user=""]In the reference design, L5 = 1.0 nH is placed between DECRF and DECA, and C8 = 1.0 pF is connected across the two nodes.
Could you please clarify:

What are the specific purposes of the 1.0 nH inductor and the 1.0 pF capacitor?

[/quote]

Its a tank circuit used to filter. No need to change these, keep them as is.

[quote user=""]C7 marked as NC/DNP in the reference design
In the same network, C7 is currently marked as NC/DNP.
Could you please clarify:[/quote]

Sometimes we have a few components marked N.C, these have often be used during testing and development, but have later been removed as deemed not needed.

[quote user=""]Power-up / power-down timing of VDD, VBUS, and nRESET
Could you please provide or confirm:[/quote]

https://docs.nordicsemi.com/r/bundle/ps_nrf54lm20a/page/regulators.html
VBUS or the USB has its own regulator so this does not have critical timing requirements.

[quote user=""]Main DC/DC related to DCC/DECD
For the main DC/DC regulator associated with DCC/DECD, could you please clarify: [/quote]

Components are mandatory can can not be changed.

The inductor values should follow similar specs.

Idc = 350mA

Isat = 120mA

DCR = 0.65 Ohm Max

Regards,
Jonathan