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Dual USB-C Expansion Card

The Dual USB-C Expansion Card is a long-running community project to create an expansion card with two USB-C ports for Framework laptops. Since Framework only offers single-port USB-C expansion cards, the community has been working on dual-port designs since June 20211. Multiple independent efforts have emerged over the years, each with different approaches, capabilities, and outcomes.

Background​

Framework's expansion card system allows users to choose their ports, but each card provides only one port. The original community thread was started by Daniel_Gilbert in June 2021, who created physical mockups of a 2-port USB-C card using Framework's open-source ExpansionCards reference designs1. Framework VP nrp confirmed the concept was feasible as a USB hub, noting the difficulty was preserving DisplayPort Alt Mode and power input passthrough1.

Framework engineer Kieran_Levin identified key technical challenges: the need for SuperSpeed signal muxing to support reversible USB-C plugs, power splitting from the 15 W upstream limit across two downstream ports, and Type-C signalling without dedicated PD controllers1. He recommended Microchip parts such as the USB5826C that integrate hub and multiple Type-C downstream port support1.

Projects​

tbe's Dual USB-C Expansion Card​

Community member tbe produced the most advanced open-source prototype. Their design uses two PCBs — a main board holding the two USB-C ports and most components, and a smaller daughterboard for the internal USB-C plug with a board-to-board connector to offset the port to the correct height23.

Prototype / In Development

This project reached the prototyping stage with assembled boards, but has not been produced at scale.

By August 2023, tbe had populated the bottom side of the PCB and was working on the top side containing the main IC, voltage converter, and connectors2. The design supports USB 3 data speeds. As of early 2026, others in the community have continued work based on tbe's open-source design files, exploring production through JLCPCB4.

Design files are available in a GitHub repository referenced from the community thread14.

Josh Cook's Dual USB-C Expansion Card​

Josh Cook (GitHub: jyancat) began a separate effort in February 2024, aiming for a more commercially polished product5. His design targeted:

  • USB 3.2 Gen 2 (10 Gbps) data speeds5
  • PD charging input on one port (initially targeting up to 28 V / 140 W, limited by thermal constraints in the expansion card enclosure)6
  • An estimated price of $20–40 USD per card5

Cook opened pre-orders via Stripe at $11 USD per card deposit, receiving significant community interest with over 200 pre-order votes5. However, the project faced repeated delays due to supply chain issues with the hub IC vendor, who reportedly stopped responding to communications6.

By late 2024, the project had stalled. Cook, who was identified as a teenager (approximately 16 years old at the time), struggled to maintain communication with pre-order customers7. His Reddit account was deleted, and the project website (i2clabs.com.au) went offline by mid-20257. Some customers reported successfully obtaining refunds, while others were unable to reach Cook7.

Stalled / Abandoned

This project appears to be abandoned. Pre-order customers who have not received refunds should contact their credit card provider or email [email protected].

David_Choi / Pedro_Manuel_Martin​

As of early 2026, community members David_Choi and Pedro_Manuel_Martin have expressed interest in continuing development of dual USB-C expansion card designs4. Pedro_Manuel_Martin has indicated plans for a complete product, and David_Choi paused his own work to avoid fragmenting the limited market4.

DockFrame Contribution​

A contributor from the DockFrame project — a modular USB-C hub that accepts Framework-compatible expansion cards — has also explored a dual USB-C card design focused on USB 3.x data (hub-based, no Alt Mode, no USB4, no PD), with emphasis on signal integrity within the Framework expansion bay's mechanical constraints4.

Technical Challenges​

All dual USB-C expansion card projects face common engineering challenges inherent to the expansion card form factor:

ChallengeDetails
PCB SpaceTwo USB-C receptacles plus a hub IC, passives, and the internal USB-C plug must fit in a 38 × 7 × 30 mm envelope1
SuperSpeed MuxingUSB-C ports require muxing of SuperSpeed (SS) differential pairs to support reversible plug orientation1
Power BudgetThe upstream expansion card slot provides max 15 W (5 V, 3 A), which must be split across two downstream ports and the hub IC itself (~1 W)1
DisplayPort Alt ModeNo community design supports DP Alt Mode passthrough; preserving it through a hub architecture is extremely difficult1
USB4 / ThunderboltNo community design supports USB4 or Thunderbolt passthrough5
Thermal ConstraintsPD charging ICs generate significant heat in the small enclosure, limiting charging voltage to approximately 28 V6
ManufacturingSmall production runs of custom PCBs with fine-pitch components require specialized assembly (reflow soldering)2

Technical Specifications​

Specificationtbe's DesignJosh Cook's Design
USB DataUSB 3 (5 Gbps)USB 3.2 Gen 2 (10 Gbps)
PD ChargingNoYes, one port (up to 28 V)
DisplayPort Alt ModeNoNo
USB4 / ThunderboltNoNo
Power per PortUp to 7.5 W (5 V, 1.5 A)Up to 7.5 W (5 V, 1.5 A)
PCB2-board design (main + daughterboard)Single board
Design FilesOpen-source1Closed5
StatusPrototype assembled2Abandoned7

Compatibility​

Dual USB-C expansion cards, if completed, would be compatible with all Framework laptops that support expansion cards:

  • Framework Laptop 13 (all generations)
  • Framework Laptop 16
  • Framework Desktop

USB data and power capabilities may vary depending on the specific expansion card slot and platform (Intel vs. AMD)8.

  • DongleHider+ — A community expansion card that hides a USB dongle internally while providing an external USB-A port via a built-in USB hub
  • DockFrame — A modular USB-C hub compatible with Framework expansion cards, also developing its own dual USB-C card9
  • EC Card 2 — A closed-case debugging (CCD) expansion card for embedded controller access, funded through Framework's Expansion Card Developer Program

Footnotes​

  1. Dual USB-C Expansion Card — Framework Community (June 2021) ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11

  2. Dual USB-C expansion card for Framework Laptop — SFF GEEK (August 2023) ↩ ↩2 ↩3 ↩4

  3. tbe prototype update (post #247) — Framework Community (September 2023) ↩

  4. Recent thread developments (post #520+) — Framework Community (February 2026) ↩ ↩2 ↩3 ↩4 ↩5

  5. Josh Cook's dual USB-C expansion card — Framework Community (February 2024) ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  6. Josh Cook's project update (post #185+) — Framework Community (July 2024) ↩ ↩2 ↩3

  7. Josh Cook's project final posts (post #227) — Framework Community (March 2026) ↩ ↩2 ↩3 ↩4

  8. USB-C Expansion Card specs — Framework ↩

  9. DockFrame — HW Media Lab LLC ↩