## Overview of the USB2533 The **USB2533** is a high-performance, power-optimized USB 2.0 Hub Controller designed by Microchip Technology. It is specifically engineered for embedded systems where low power consumption and a small footprint are critical. It features three downstream ports and incorporates **MultiTRAK™** technology for high-speed data transfers. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **USB Standard** | USB 2.0 (High-Speed, Full-Speed, Low-Speed) | | **Downstream Ports** | 3 Ports | | **Upstream Port** | 1 Port | | **Package** | 36-pin SQFN (6x6 mm) | | **Operating Voltage** | 3.3V (Internal 1.2V regulator) | | **Operating Temp** | Commercial (0°C to 70°C) & Industrial (-40°C to 85°C) | --- ### 2. Core Electronic Components & Features #### A. MultiTRAK™ Technology Unlike standard hubs that share a single Transaction Translator (TT) among all ports, the USB2533 utilizes **dedicated Transaction Translators** for every downstream port. This prevents data bottlenecks when multiple Full-Speed (12 Mbps) or Low-Speed (1.5 Mbps) devices are connected simultaneously with High-Speed devices. #### B. Battery Charging (BC1.2) The controller supports advanced battery charging features, allowing it to act as a: * **CDP (Charging Downstream Port):** Data transfer + High current charging. * **DCP (Dedicated Charging Port):** High current charging without data. * **Custom Profiles:** Support for Apple® and legacy devices. #### C. FlexConnect This is a unique feature that allows the "role reversal" of the USB ports. Through software commands, the upstream port and a designated downstream port can swap roles, which is highly useful in automotive infotainment systems. #### D. Configuration Interfaces The USB2533 can be configured in three ways: 1. **Default:** Operates as a plug-and-play hub with internal defaults. 2. **SMBus:** Allows an external microcontroller to configure registers via an $I^2C$ compatible interface. 3. **External EEPROM:** Loads configuration settings automatically upon power-up. --- ### 3. Pinout Functional Groups | Group | Function | | :--- | :--- | | **USB Signals** | `DP[3:0]`, `DM[3:0]` (Differential pairs for data) | | **Power** | `VDD33` (3.3V Input), `VDD12` (Internal Regulator Output) | | **Control/Config** | `RESET_N`, `SDA/SMBDATA`, `SCL/SMBCLK` | | **Status LEDs** | `LED[3:1]` (Indicates port activity or power status) | | **Clock** | `XTAL1 / XTAL2` (Requires a 24MHz Crystal or Oscillator) | --- ### 4. Application Circuit Example (Simplified) ```mermaid graph LR A[5V Power Source] --> B[3.3V LDO Regulator] B --> C(USB2533 Hub IC) D[24MHz Crystal] --- C C --> E[Port 1: USB Device] C --> F[Port 2: USB Device] C --> G[Port 3: USB Device] H[Upstream: SOC/PC] --- C ``` ---