Power ManagementのトピックRe: NX20P0477UKZ moisture detection

NX20P0477UKZ moisture detection

kadamm — Wed, 08 Apr 2026 08:06:07 GMT

Hello Team,

We are planning to use P/N: NX20P0477UKZ in our design. Currently, we do not intend to use a dedicated CC controller. Instead, we plan to implement a 4.7kΩ pull-up resistor to 3.3 V or 10kΩ pull-up resistor to 5V on the CC line to advertise a source capability of 5V at 3A. Our application is for Mobile charging.

Could you please advise whether this approach is appropriate, or if it is recommended to use a dedicated CC controller?

Additionally, we would appreciate your guidance on the suitable resistor and capacitor combinations to validate this implementation as a POC.

Regards,

Kadam

Re: NX20P0477UKZ moisture detection

JozefKozon — Wed, 08 Apr 2026 11:08:33 GMT

Hello Kadamm,

NX20P0477UKZ is fine as a VBUS power‑path/protection switch. However a simple pull‑up to 3.3 V or arbitrary resistor values is not USB‑C compliant.

For a POC, you may avoid a CC controller only if the design is:

Source‑only
Fixed 5 V
No USB‑PD, no role swap

Capacitors (Typical)

VBUS: 10–22 µF bulk + 1 µF + 100 nF near NX20P0477
Add ESD/TVS protection on CC and VBUS (recommended)

Resistor‑only CC is acceptable for a quick POC

For a real mobile charger, use a dedicated CC controller (e.g. PTN5110 / PTN5150) for:

Better phone compatibility
Cable current safety
USB‑C compliance

With Best Regards,

Jozef

Re: NX20P0477UKZ moisture detection

kadamm — Wed, 08 Apr 2026 11:28:06 GMT

Hello Josef,

Could you please help us with resistor and capacitor value combination to simulate moisture detection functionality without any water droplets on USB connector?

Regards,

Kadam

Re: NX20P0477UKZ moisture detection

JozefKozon — Wed, 08 Apr 2026 11:40:39 GMT

Hello Kadam,

water lowers this resistance into the 10 kΩ–1 MΩ range, triggering detection. Place a high‑value resistor temporarily across CC pins or CC to GND.

Connections (choose one):

CC1 → GND
CC2 → GND
CC1 → CC2

Simulation Level	Resistor Value
Light moisture	1 MΩ
Moderate moisture	330 kΩ – 470 kΩ
Heavy moisture	47 kΩ – 100 kΩ

To emulate slow RC behavior of moisture, add 10 nF – 100 nF in parallel with the resistor.

With Best Regards,

Jozef