molecule

USB3.0 to Ethernet Molecule

Public Made by Adom

by adom

USB-C to Gigabit Ethernet (data-only) adapter board on the Microchip LAN7800. Self-contained: bundles the complete KiCad library (29 symbols, 16 footprints, 15 3D models) AND links all 28 components as dependencies.

boardmoleculeusb3ethernetlan7800usb-ckicad-libraryadom-lbr
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Made with KiCad 10.0 · needs KiCad 10.0 or later to open · KiCad file format 20260306
Name Last commit message Last updated
ct Rebuild page: interactive Assembly/Static 3D board viewer, section board maps, generated BOM and provenance, new dark h… · barrett-land 3mo ago
docs Rebuild page: interactive Assembly/Static 3D board viewer, section board maps, generated BOM and provenance, new dark h… · barrett-land 3mo ago
render 3D model: add the USB-C receptacle (J2, USB4115-03-C) · Caleb 8d ago
screenshots Set hero asset · barrett-land 3mo ago
USB3toEthernetDataOnly.3dshapes board 6/7 · barrett-land 3mo ago
USB3toEthernetDataOnly.pretty Board rev: U2 LMV331IDBVR -> TL331LV (fixes inverted CC orientation), crystal reworked to 0deg with shorter XI/XO · barrett-land 2mo ago
viewers rename: adom-layout-viewer -> adom-2dboard, adom-schematic-viewer -> adom-schematic · barrett-land 2mo ago
adom-3d-viewer.min.js Rebuild page: interactive Assembly/Static 3D board viewer, section board maps, generated BOM and provenance, new dark h… · barrett-land 3mo ago
board-index.json Rebuild tagged board model from current revision: USB-C (J2) now upright, crystal rework included, Z-up and origin-cent… · barrett-land 2mo ago
board-viewer.html Rebuild page: interactive Assembly/Static 3D board viewer, section board maps, generated BOM and provenance, new dark h… · barrett-land 3mo ago
board.glb Rebuild tagged board model from current revision: USB-C (J2) now upright, crystal rework included, Z-up and origin-cent… · barrett-land 2mo ago
data.kicad_sch Restore current (new) design + version 1.3.0 · barrett-land 3mo ago
ethernet.kicad_sch Restore current (new) design + version 1.3.0 · barrett-land 3mo ago
export.json Add fabrication sources and export provenance for molecule builds · AdityaAngajala 5d ago
package.json Publish 1.4.0 · barrett-land 2mo ago
page.json Publish 1.4.0 · barrett-land 2mo ago
power.kicad_sch Restore current (new) design + version 1.3.0 · barrett-land 3mo ago
readme.html rename: adom-layout-viewer -> adom-2dboard, adom-schematic-viewer -> adom-schematic · barrett-land 2mo ago
README.html Page copy: U2 is now TL331LV (reversed-input comparator); dep link retargeted to tl331lv · barrett-land 2mo ago
README.md Publish 1.4.0 · barrett-land 2mo ago
usb.kicad_sch Board rev: U2 LMV331IDBVR -> TL331LV (fixes inverted CC orientation), crystal reworked to 0deg with shorter XI/XO · barrett-land 2mo ago
usb3-to-ethernet-dataonly-molecule-fab.zip Add fabrication sources and export provenance for molecule builds · AdityaAngajala 5d ago
USB3toEthernetDataOnly_Molecule.kicad_pcb Board rev: U2 LMV331IDBVR -> TL331LV (fixes inverted CC orientation), crystal reworked to 0deg with shorter XI/XO · barrett-land 2mo ago
USB3toEthernetDataOnly_Molecule.kicad_pro Board rev: U2 LMV331IDBVR -> TL331LV (fixes inverted CC orientation), crystal reworked to 0deg with shorter XI/XO · barrett-land 2mo ago
USB3toEthernetDataOnly_Molecule.kicad_sch Fix MachinePin symbol lib_id (footprint-library_BLT -> symbol-library) in root schematic · barrett-land 2mo ago
USB3toEthernetDataOnly.kicad_sym Publish 1.4.0 · barrett-land 2mo ago
viewer-config.json Rebuild page: interactive Assembly/Static 3D board viewer, section board maps, generated BOM and provenance, new dark h… · barrett-land 3mo ago

USB3.0 to Ethernet Molecule

USB-C to Gigabit Ethernet data-only adapter, built around the Microchip LAN7800 USB-to-Ethernet controller with a TI HD3SS3212 USB3 mux steered by a TL331LV comparator off the USB-C CC pins, NCP1117-3.3 LDO, M93C66 config EEPROM, 25 MHz crystal, and passives. Categorized as a board.

Components (dependencies)

The board depends on its 28 components; each is its own wiki component page (symbol + footprint + 3D + adom-lbr JSON):

  • cl05a106mq5nunc — CL05A106MQ5NUNC (Capacitor, 4x)
  • cl05b104ko5nnnc — CL05B104KO5NNNC (Capacitor, 7x)
  • cl10a106kp8nnnc — CL10A106KP8NNNC (Capacitor, 1x)
  • 0402b103k500nt — 0402B103K500NT (Capacitor, 2x)
  • 0402cg180j500nt — 0402CG180J500NT (Capacitor, 2x)
  • cl05a105ka5nqnc — CL05A105KA5NQNC (Capacitor, 2x)
  • kt-0603b — KT-0603B (LED, 1x)
  • kt-0603r — KT-0603R (LED, 1x)
  • blm15ag601sn1d — BLM15AG601SN1D (Ferrite Bead, 3x)
  • usb4115-03-c — USB4115-03-C (Connector, 1x)
  • hc-rj45-511q-1-2 — HC-RJ45-511Q-1-2 (Connector, 1x)
  • fnr3015s3r3mt — FNR3015S3R3MT (Inductor, 1x)
  • adom-machinepin-large-short — MachinePinLargeShort (Mechanical, 4x)
  • rc0402fr-07300rl — RC0402FR-07300RL (Resistor, 2x)
  • 0402wgf4301tce — 0402WGF4301TCE (Resistor, 1x)
  • 0402wgf5101tce — 0402WGF5101TCE (Resistor, 2x)
  • cr-02fl6-1m — CR-02FL6----1M (Resistor, 1x)
  • 0402wgf7681tce — 0402WGF7681TCE (Resistor, 1x)
  • 0402wgf2201tce — 0402WGF2201TCE (Resistor, 1x)
  • 0402wgf2001tce — 0402WGF2001TCE (Resistor, 1x)
  • 0402wgf1202tce — 0402WGF1202TCE (Resistor, 1x)
  • skrpace010 — SKRPACE010 (Switch, 1x)
  • lan7800-i-y9x — LAN7800-I/Y9X (IC, 1x)
  • tl331lv — TL331LV (IC, 1x)
  • ncp1117st33t3g — NCP1117ST33T3G (IC, 1x)
  • m93c66-wmn6tp — M93C66-WMN6TP (IC, 1x)
  • hd3ss3212irksr — HD3SS3212IRKSR (IC, 1x)
  • x322525mob4si — X322525MOB4SI (Crystal, 1x)

USB-C orientation detection

The HD3SS3212 SuperSpeed mux is steered by U2, a single comparator wired across the USB-C CC pins (CC1 and CC2, each with a 5.1k Rd). The connected CC pin sits higher than the idle one, so the comparator resolves plug orientation and drives the mux SEL pin through a 5.1k pull-up to VDDVARIO.

U2 is a TL331LV, chosen for its reversed input pinout (IN- on pin 1, IN+ on pin 3). Fitting it in place of a common-pinout SOT-23-5 comparator inverts the orientation decision with no layout change, which is what makes SEL select the correct mux port in both plug orientations:

Plug orientation CC state U2 output SEL Mux routes to
CC1 active CC1 > CC2 pulls low LOW Port B (USB3_1*, J2 A2/A3 + B10/B11)
CC2 active CC2 > CC1 releases high HIGH Port C (USB3_2*, J2 B2/B3 + A10/A11)

Note that a common-pinout part (for example LMV331) is a mechanical drop-in here but inverts this decision, which breaks SuperSpeed link training in both orientations while leaving USB 2.0 unaffected.

Bundled KiCad library

This page also ships the complete, self-contained KiCad library for the board: 29 symbols, 16 footprints, 15 3D models (STEP + GLB), all linked.

  • USB3toEthernetDataOnly.kicad_sym: all 29 schematic symbols
  • USB3toEthernetDataOnly.pretty/: 16 footprints
  • USB3toEthernetDataOnly.3dshapes/: 15 STEP + GLB models

Install

  1. Download this page's files and extract, e.g. ~/Documents/KiCAD/USB3toEthernetDataOnly/.
  2. KiCad → Preferences → Configure Paths, add USB3TOETH_3D = <extract-dir>/USB3toEthernetDataOnly.3dshapes (so footprint 3D models resolve).
  3. Add to your sym-lib-table / fp-lib-table:
    (lib (name "USB3toEthernetDataOnly")(type "KiCad")(uri "<extract-dir>/USB3toEthernetDataOnly.kicad_sym")(options "")(descr "USB3-to-Ethernet Molecule symbols"))
(lib (name "USB3toEthernetDataOnly")(type "KiCad")(uri "<extract-dir>/USB3toEthernetDataOnly.pretty")(options "")(descr "USB3-to-Ethernet Molecule footprints"))