onsemi FUSB302B10MPX USB Type-C Port Controller: Datasheet, Features, and Application Circuit Design

The onsemi FUSB302B10MPX is a highly integrated, autonomous USB Type-C port controller designed to manage the complexities of the USB Power Delivery (PD) protocol. It serves as a complete interface solution for devices requiring robust power negotiation and data role swapping capabilities, making it an essential component in modern consumer electronics, peripherals, and power adapters.

Key Features and Datasheet Highlights

The FUSB302B10MPX excels with a comprehensive feature set tailored for the USB Type-C standard. Its programmable functionality allows it to operate as a Downstream Facing Port (DFP—source), Upstream Facing Port (UFP—sink), or a Dual-Role Port (DRP), providing immense design flexibility. A core strength is its integrated USB Power Delivery physical layer (PHY), which handles all the low-level BMC (Biphase Mark Coding) protocol encoding and decoding, offloading this task from the main system processor.

The controller incorporates a voltage monitoring system on the CC (Configuration Channel) pins to detect port attachment and connection orientation. It supports dead battery mode, a critical feature that allows a device with a completely discharged battery to still be powered by a source. Furthermore, it includes I²C programmable interrupt outputs for efficient communication with a host microcontroller, simplifying system integration and control.

Application Circuit Design

Designing with the FUSB302B10MPX is streamlined by its minimal external component requirement. A typical application circuit for a USB-C sink (UFP) device involves the following key elements:

1. Power Supply: The IC is typically powered from a 3.3V system rail. Proper decoupling with capacitors (e.g., 100nF and 1µF) close to the VDD pin is essential for stable operation.

2. CC Pins Connection: The CC1 and CC2 pins are directly connected to the corresponding pins of the USB Type-C receptacle. Internal pull-down resistors are integrated for UFP detection, simplifying the PCB layout.

3. VBUS Sensing: While not always mandatory, a voltage divider circuit can be added to monitor VBUS voltage through an external ADC, providing an extra layer of system protection.

4. I²C Communication: The SDA and SCL lines require pull-up resistors to the 3.3V logic level. The INT_N (interrupt) output alerts the host MCU when a PD message is received or a status change occurs, enabling event-driven firmware.

5. GPIOs: The general-purpose input/output pins can be configured for various functions, such as controlling an external load switch for VBUS power path management.

For a robust design, careful attention must be paid to ESD protection on the CC and VBUS lines, as mandated by the USB specification. Placing TVS diodes close to the connector is a standard practice to safeguard the controller from electrostatic discharge events.

ICGOODFIND Summary

The onsemi FUSB302B10MPX stands out as a versatile and powerful solution for implementing USB Type-C with Power Delivery. Its autonomous operation reduces firmware overhead, its integrated PHY simplifies the bill of materials, and its support for critical features like dead battery mode ensures end-user satisfaction. It is an optimal choice for designers seeking a reliable, cost-effective, and compact controller to add modern USB-C connectivity to their products.

Keywords: USB Power Delivery (PD), Type-C Port Controller, Configuration Channel (CC), Dead Battery Mode, Biphase Mark Coding (BMC)