USB2532 HUB-C
USB 2.0 hub molecule based on the Microchip USB2532I — 38×38 mm, 1 upstream + 2 downstream USB-C ports, self-powered with on-board 3.3V LDO, I2C EEPROM for configuration, and 30 machine contacts + 4 machine pins. Designed for Adom workcell USB distribution.
How It Works
The three USB-C 2.0 connectors are the primary user-facing interface for this molecule. J1 (upstream) connects to the USB host; J2 and J3 (downstream) connect to USB devices. The downstream ports provide power delivery to connected devices via per-port power switches (AP22615) with overcurrent protection.
All input power comes through the machine contacts only — the hub does not draw power from the upstream USB host. The workcell +5V rail feeds in through MP1/MP2 and MC20–MC22, powering the hub IC, the 3.3V LDO, and the downstream port power switches. This self-powered topology means downstream devices get full 5V power from the workcell supply regardless of what the USB host can source.
Overview
| Property |
Value |
| Molecule ID |
usb2532-hub-c |
| Board Size |
38.0 × 38.0 mm |
| Hub IC |
USB2532I-1080AEN (Microchip, QFN-36) — USB 2.0, 2-port hub |
| EEPROM |
24LC04BT-I/OT — 4 Kbit I2C, stores hub configuration |
| Regulator |
MCP1725T-ADJE/MC — adjustable LDO, set for 3.3V |
| Power Switches |
2× AP22615AWU — per-port power control with overcurrent protection |
| ESD Protection |
3× TPD2EUSB30DRTR — one per USB-C port |
| USB Ports |
J1 (upstream UFP), J2 (downstream port 1), J3 (downstream port 2) |
| Crystal |
24 MHz |
| Machine Contacts |
30 contacts + 4 corner machine pins |
| KiCad Version |
7/8 |
| Design Reference |
SMSC EVB-USB2534BC-01 evaluation board |
Key ICs
| Ref |
Part |
Package |
Function |
| U4 |
USB2532I-1080AEN |
QFN-36 |
USB 2.0 hub controller, 2 downstream ports |
| U7 |
24LC04BT-I/OT |
SOT-23-5 |
4 Kbit I2C EEPROM for hub configuration |
| U5 |
MCP1725T-ADJE/MC |
DFN-8 |
Adjustable LDO regulator (3.3V output) |
| U1 |
AP22615AWU |
SOT-23-5 |
Port 1 power switch with OCS |
| U3 |
AP22615AWU |
SOT-23-5 |
Port 2 power switch with OCS |
| U6 |
TPD2EUSB30DRTR |
DRT-3 |
Upstream USB ESD protection |
| U8 |
TPD2EUSB30DRTR |
DRT-3 |
Downstream port 1 ESD protection |
| U9 |
TPD2EUSB30DRTR |
DRT-3 |
Downstream port 2 ESD protection |
Machine Contact Pin Mapping
4 corner machine pins + 30 machine contacts on all 4 edges.
Corner Machine Pins
| Pin |
Position |
Net |
Function |
| MP1 |
Top-left (16, 24) |
+5V |
5V power input |
| MP2 |
Top-right (48, 24) |
+5V |
5V power input |
| MP3 |
Bottom-left (16, 56) |
GND |
Ground |
| MP4 |
Bottom-right (48, 56) |
GND |
Ground |
Left Edge — Control & Config
| Contact |
Net |
Function |
| MC19 |
GND |
Ground |
| MC17 |
/RX |
UART RX (hub debug) |
| MC18 |
/TX |
UART TX (hub debug) |
| MC16 |
+3V3 |
3.3V output |
| MC1 |
/SCL/CFG_SEL0 |
I2C clock / config strap 0 |
| MC2 |
/SDA/SMBDATA |
I2C data / SMBus data |
| MC3 |
/RESET |
Hub reset |
| MC5 |
GND |
Ground |
| MC4 |
/VBUS_DET |
Upstream VBUS detect |
Top Edge — Power
| Contact |
Net |
Function |
| MC20 |
+5V |
5V power |
| MC21 |
+5V |
5V power |
| MC22 |
+5V |
5V power |
| MC23 |
GND |
Ground |
| MC24 |
GND |
Ground |
| MC25 |
GND |
Ground |
Right Edge — USB Data & Downstream
| Contact |
Net |
Function |
| MC27 |
/CC2_2 |
Port 2 CC2 |
| MC28 |
/USB2_DP |
Port 2 USB D+ |
| MC29 |
/USB2_DN |
Port 2 USB D- |
| MC30 |
GND |
Ground |
| MC26 |
/PWR2 |
Port 2 power enable |
| MC7 |
/CC2_1 |
Port 1 CC2 |
| MC8 |
/USB1_DP |
Port 1 USB D+ |
| MC9 |
/USB1_DN |
Port 1 USB D- |
| MC10 |
GND |
Ground |
| MC6 |
/PWR1 |
Port 1 power enable |
Bottom Edge — Upstream USB
| Contact |
Net |
Function |
| MC11 |
/VBUS_UP |
Upstream VBUS |
| MC12 |
/CC2_0 |
Upstream CC2 |
| MC13 |
/USB_UP_DP |
Upstream USB D+ |
| MC14 |
/USB_UP_DN |
Upstream USB D- |
| MC15 |
GND |
Ground |
Configuration Modes
The hub supports two configuration modes selected via solder jumpers:
| Mode |
CFG_SEL1 (JP5) |
CFG_SEL0 (JP4) |
Use |
| Straps & OTP, Self Pwr |
0 (open) |
0 (open) |
Initial bring-up, blank EEPROM |
| I2C EEPROM & OTP |
1 (bridged) |
1 (bridged) |
After EEPROM is programmed |
JP3 bridges SDA to +3V3 (I2C pull-up).
Power Architecture
+5V input (MC20-22 or MP1/MP2)
│
├─→ FB1 (ferrite bead) → VBUS upstream (J1)
├─→ U1 (AP22615) → Port 1 power (J2)
├─→ U3 (AP22615) → Port 2 power (J3)
└─→ U5 (MCP1725) → +3V3 (hub logic, EEPROM)
Self-powered topology — the hub provides power to downstream ports from the workcell +5V rail, not from the upstream USB host.
Status LEDs
| LED |
Color |
Function |
| D1 |
Green |
3.3V power good |
| D2 |
Red |
Reset indicator |
| D3 |
Yellow |
Hub activity |
| D4 |
Green |
Port 1 power good |
| D5 |
Red |
Overcurrent fault |
| D6 |
Green |
Port 2 power good |
Solder Jumpers
| Jumper |
Default |
Function |
| JP1 |
Bridged |
Port 1 power enable routing |
| JP2 |
Bridged |
Port 2 power enable routing |
| JP3 |
Bridged |
SDA I2C pull-up |
| JP4 |
Bridged |
CFG_SEL0 (config mode select) |
| JP5 |
Bridged |
CFG_SEL1 (config mode select) |
EEPROM & Firmware
The project includes firmware tools for EEPROM programming:
firmware/eeprom.bin — pre-built EEPROM binaryfirmware/usb2532_eeprom.py — Python programming scripttest/EEPROM_PROGRAMMING_GUIDE.md — programming instructionstest/USB2532_Config_v1.2.json — hub configurationtest/USB2532_HUB-C_Test_Procedure.md — full functional test procedure
Debug & Test Points
| Test Point |
Signal |
Function |
| TP1 |
— |
General probe point |
| TP2 |
— |
General probe point |
| TP3 |
— |
General probe point |
| SW1 |
RESET |
Manual hub reset button |
Fabrication
KiCad project files included. STEP model available for mechanical integration.
3D Models
USB2532_HUB-C.glb — assembled board GLBUSB2532_HUB-C.step — STEP model for mechanical CAD
