Technical Query: nRF5340-DK regulator current capabilities

Question

We are developing a multimodal optical, biometric, and motion sensing platform utilizing the nRF5340-DK (PCA10095, v2.0.0) as the master controller and wireless host. The system interfaces with an Analog Devices EVAL-ADPD4100-ARDZ optical AFE shield mounted on the Arduino Rev3 headers, alongside a Custom Sensor PCB housing 6 optical LEDs, 2 PIN photodiodes, an accelerometer (ADXL367), a precision temperature sensor (TMP117), and a force-sensing resistor (FSR400). 
 
 The board is powered via USB (5V VBUS on J2/J3). To ensure system stability and avoid noise coupling into the nRF5340 SoC, we have evaluated the power distribution across the 3.0V VDD and 5.0V V5V rails. We would appreciate your review and guidance on our proposed power architecture.

1. 3.0V VDD Power Domain (Supplied via XC9236 Buck Regulator, rated 600 mA max) 
 
 nRF5340 SoC (Application Core + Network Core + BLE active TX/RX @ +3 dBm): ~35.0 mA 
 SEGGER J-Link OB Interface MCU (VDD_IMCU via U19): ~25.0 mA 
 MX25R6435F 64 Mb QSPI Flash (VDD_PER): ~15.0 mA 
 Onboard LEDs & Analog Signal Switches (FSA2466): ~20.0 mA 
 ADPD4100 AFE Core + Custom PCB Sensors (TMP117, ADXL367, FSR400): ~4.8 mA 
 Total 3.0V VDD Load: ~99.8 mA (~300 mW) (Well within the 600 mA XC9236 regulator limit) 
 
2. 5.0V V5V Power Domain (Sourced via USB VBUS / XC9131 Boost Converter) (Note: This is not the 5V rail directly from the USB connector) 
 
 3.0V Buck Regulator Input (Sourcing ~300 mW @ ~90% efficiency): ~66.3 mA 
 Custom PCB Optical LED Rail (Driven via ADPD4100 low-side sink drivers; max single LED drive up to 400 mA peak/CW for Luminus SST-10 Deep Red/Far Red): 400.0 mA 
 Total 5.0V V5V Load: ~466.3 mA (~2.33 W total USB power) 
 
 Engineering Questions for Nordic Support

5V Rail (V5V) Current Capability & Protection Limits: 
 
Pin 5 of Header P1 provides the V5V rail on the DK. 
 Sourcing ~467 mA total continuous/pulsed load on this 5V rail approaches the ~500 mA rating of standard USB 2.0 ports and board ferrite beads (e.g., FB1–FB6 rated at 0.55A). Question: Does the onboard power distribution path (XC9131 boost converter, protection diodes D3/D5/D6, and reverse-protection switches) support a continuous or pulsed 470 mA draw on V5V without thermal overstress or voltage sags?

Transient Noise Coupling & RF Performance: 
 
Driving high-power LEDs in pulsed mode creates rapid 400 mA current steps on the 5V rail. Question: What bulk decoupling / ferrite filtering topology does Nordic recommend on custom Arduino shields to prevent switching transients on V5V from modulating the regulated 3.0V VDD_nRF rail or degrading the 2.4 GHz BLE receiver sensitivity?

Current Measurement Integrity on Header P22: 
 
We plan to measure the nRF5340 SoC active/sleep current using a Power Profiler Kit (PPK2) or oscilloscope across header P22 (with SB40 cut). Question: Since the 400 mA LED current flows through the 5V domain and sinks through the ADPD4100 driver to board GND, can you confirm that this high 5V current path is completely isolated from the P22 (VDD_nRF) measurement loop and won't introduce measurement artifacts?

External 5V Sourcing Recommendation: 
 
 Based on this evaluation, should we use a separate regulator on the custom PCB to generate 5V and how can we source the 3V output from the nRF5340 DK for external use?

What is the current capabilities of the 5V and 3V regulators on the nrF5340 DK. Will it be able to power all the loads as per my startegy explained at the start of the email

Note: BLE or radio transmission will not be active while the LEDs are taking measurements.