The **STUSB4700** is a standalone USB Power Delivery (PD) controller designed by STMicroelectronics. It is specifically engineered to handle power negotiation on the "Source" (Provider) side, making it ideal for AC adapters, power strips, and chargers. --- ## 1. Key Technical Specifications The STUSB4700 is designed to manage the USB Type-C and PD ecosystem without requiring an external microcontroller for basic operations. | Parameter | Specification | | :--- | :--- | | **Input Voltage (VCC)** | 4.1V to 22V | | **PD Profiles** | Up to 5 configurable Power Data Objects (PDOs) | | **Communication** | I2C Interface (for optional configuration) | | **Package** | QFN24 (4x4 mm) | | **USB Version** | USB Type-C Rev 1.2 / USB PD Rev 2.0 | | **Protection** | VBUS Overvoltage, Short-circuit protection | --- ## 2. Core Functional Blocks To understand how the STUSB4700 operates, it is helpful to look at its internal architecture: ### A. Configuration Channel (CC) Logic The chip monitors the CC1 and CC2 pins to detect when a device is attached. It handles the orientation detection and determines the initial current capability (Standard USB, 1.5A, or 3.0A). ### B. Non-Volatile Memory (NVM) One of the standout features is the integrated NVM. This allows developers to pre-program the desired voltage and current profiles (PDOs). Once programmed, the chip functions autonomously. ### C. Gate Drivers The device includes internal circuitry to drive external N-channel MOSFETs. This allows it to safely enable or disable the **VBUS** power path based on successful negotiation. ### D. Discharge Circuitry When a device is unplugged or a lower voltage is negotiated, the STUSB4700 has an internal discharge path to quickly drop the VBUS voltage to a safe level, protecting the connected hardware. --- ## 3. Typical Application Schematic Components When integrating the STUSB4700, the following electronic parts are usually required: 1. **N-Channel MOSFETs:** Used as power switches to control the flow from the DC source to the USB-C connector. 2. **Sensing Resistor:** Used for overcurrent protection and monitoring. 3. **Capacitors:** Decoupling capacitors (typically 100nF and 1µF) are required on the VCC and VDD pins for stability. 4. **TVS Diodes:** Essential on the CC1/CC2 and VBUS lines to protect the controller from Electrostatic Discharge (ESD). --- ## 4. Example Programming Setup While it can run standalone, you can interface with it using the I2C protocol to change settings dynamically. ```c // Pseudocode for reading the Status Register via I2C #define STUSB4700_ADDR 0x28 #define STATUS_REG 0x0B uint8_t read_status() { I2C_Start(STUSB4700_ADDR); I2C_Write(STATUS_REG); uint8_t status = I2C_Read(); I2C_Stop(); return status; } ```