# Article: What is USB-C Power Delivery (PD) pass-through?

**URL:** <https://community.startech.com/t/article-what-is-usb-c-power-delivery-pd-pass-through/816>\
**Category:** Docks, Hubs, Display Adapters\
**Created:** [January 17, 2022, 12:06pm UTC](https://community.startech.com/t/article-what-is-usb-c-power-delivery-pd-pass-through/816 "2022-01-17T12:06:42Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![malcolm](https://yyz2.discourse-cdn.com/flex012/user_avatar/community.startech.com/malcolm/32/17_2.png) [@malcolm](https://community.startech.com/u/malcolm)\
**Post date:** [January 17, 2022, 12:06pm UTC](https://community.startech.com/t/article-what-is-usb-c-power-delivery-pd-pass-through/816/1 "2022-01-17T12:06:42Z")

</div>

_This article was created from a community discussion by @jtan_ .

Using Power Delivery pass-through with a supported USB-C laptop, you can power the laptop and the multiport adapter/hub with your existing USB-C laptop power adapter. To ensure the hub powers and charges your laptop, your host laptop’s USB-C port must support USB Power Delivery. An existing USB-C laptop power adapter is plugged into the hub, which then “passes through” power to charge the laptop over the single USB-C connection.

**Reserved Power**

With most multiport adapters/hubs, some amount of power (commonly between 4W and 15W, depending on I/O) is reserved for hub/downstream ports. This means if a hub like our [HB30C4AFPD](https://www.startech.com/en-us/cards-adapters/hb30c4afpd) (that reserves 7.4W) is used with a 60W USB-C power adapter, only 52.6W will be provided to the laptop via PD Passthrough.

**Host USB-C Ports Without USB PD Support**

Not all USB-C ports support the full functionality of the USB Type-C standard. Multiport adapters/hubs can connect to a host laptop’s USB-C port that doesn’t support USB Power Delivery. However, in this configuration, if a power adapter is connected to the multiport adapter/hub, it will not pass power through to the host laptop.

This FAQ applies to these products: [CDP2DVIUCP](https://www.startech.com/en-us/audio-video-products/cdp2dviucp) [CDP2DVIUCPW](https://www.startech.com/en-us/audio-video-products/cdp2dviucpw) [CDP2HDUACP](https://www.startech.com/en-us/cards-adapters/cdp2hduacp) [CDP2HDUACPW](https://www.startech.com/en-us/cards-adapters/cdp2hduacpw) [CDP2HDUCP](https://www.startech.com/en-us/audio-video-products/cdp2hducp) [CDP2HDUCPW](https://www.startech.com/en-us/audio-video-products/cdp2hducpw) [CDP2VGAUACP](https://www.startech.com/en-us/cards-adapters/cdp2vgauacp) [CDP2VGAUCP](https://www.startech.com/en-us/audio-video-products/cdp2vgaucp) [CDP2VGAUCPW](https://www.startech.com/en-us/audio-video-products/cdp2vgaucpw) [HB30C3AGEPD](https://www.startech.com/en-us/cards-adapters/hb30c3agepd) [HB30C4AFPD](https://www.startech.com/en-us/cards-adapters/hb30c4afpd) [US1GC301AU](https://www.startech.com/en-us/networking-io/us1gc301au) [US1GC303APD](https://www.startech.com/en-us/networking-io/us1gc303apd) [US1GC30PD](https://www.startech.com/en-us/networking-io/us1gc30pd) [CDP2HVGUASPD](https://www.startech.com/cdp2hvguaspd) 115B-USBC-MULTIPORT 120B-USBC-MULTIPORT 122-USBC-HDMI-4K-VGA 127B-USBC-MULTIPORT CDP2HVGUASPD CDP2HVGUASPD DKT31CH2CPD3 102B-USBC-MULTIPORT HB31CM4CPD3 DKT31CMDPHPD