Project Description

This project aims to develop a 100W USB Power Delivery (PD) system that utilizes a USB Type-C port to deliver power at multiple voltage levels, making it suitable for various devices, including smartphones, fast-charging accessories, and laptops. Additionally, the same Type-C port facilitates high-speed data transfer, reducing cable clutter and enhancing connectivity. This design is applicable in scenarios such as SmartDesk workstations, where seamless power and data transfer are essential.

To accomplish this, the system integrates FUSB3307 for power negotiation, NCV81599MWTXG for voltage regulation, and TPS65987 for managing data transfer alongside power delivery.

FUSB3307 Features

The FUSB3307 is a USB PD controller responsible for negotiating power delivery between source and sink devices. Key features include:

  • USB PD 3.0 Compliance – Supports power profiles up to 100W (20V, 5A).
  • Automatic Source and Sink Detection – Dynamically determines the power role.
  • CC1 & CC2 Communication – Manages PD negotiation via configuration channels.
  • Adjustable Power Output – Works with external voltage regulation components.
  • Overcurrent and Overvoltage Protection – Enhances system safety and reliability.

Working Principle

FUSB3307 Working Mechanism & Role of CC1/CC2 Pins

  • The CC1 and CC2 pins are critical for USB Type-C power delivery and data communication. These pins detect cable orientation, identify connected devices, and manage communication between the power source and sink.
  • Through CC1 and CC2, the FUSB3307 determines whether the system should act as a power provider (source) or receiver (sink) and negotiates voltage accordingly.
  • These pins also support USB PD messaging, Alternate Mode selection, and accessory detection, ensuring compatibility with various devices.
  • If a compatible power profile is selected, the NCV81599MWTXG is triggered to deliver the appropriate voltage output.

NCV81599MWTXG: Buck-Boost Converter Working

  • Adjusts voltage dynamically based on signals from the FUSB3307.
  • Functions as a buck converter to step down voltage (e.g., from 24V to 12V) and as a boost converter to step up voltage (e.g., from 12V to 20V).
  • Monitors current levels to maintain stable power delivery and prevent overcurrent faults.
  • Uses MOSFET-based switching for high-efficiency energy conversion.

Together, the FUSB3307 and NCV81599MWTXG form a robust USB PD system capable of delivering up to 100W safely and efficiently.

USB Power Delivery Negotiation & Profiles

USB Power Delivery Negotiation Steps

The USB PD negotiation process ensures that the connected device receives the correct voltage and current levels. The process follows these steps:

  1. Connection Establishment – When a USB-C device is plugged in, the CC1 and CC2 pins detect the connection and cable orientation.
  2. Power Capability Advertisement – The FUSB3307 PD controller advertises the available power profiles to the connected device.
  3. Power Request from Device – The connected device selects an appropriate voltage and current based on its requirements.
  4. Power Delivery Agreement – The FUSB3307 validates the request and enables the necessary voltage using the NCV81599MWTXG buck-boost converter.
  5. Power Transfer Initiation – The system starts delivering the agreed power level while continuously monitoring for safety conditions.
  6. Dynamic Adjustments – If the device requires a change in power level (such as switching to fast charging), a new negotiation cycle begins.

The system supports multiple USB PD profiles, enabling devices to negotiate optimal power levels:

PD Profile Voltage (V) Current (A) Power (W)
Profile 1 5V 3A 15W
Profile 2 9V 3A 27W
Profile 3 12V 3A 36W
Profile 4 15V 3A 45W
Profile 5 20V 5A 100W
  • Sink Mode: Detects and supplies the appropriate voltage to a connected device.
  • Source Mode: Provides power to external devices when required.
  • Dual-Role Mode: Allows dynamic switching between source and sink roles.

Circuit Design & Debugging with Power-Z KT002

To ensure accurate power negotiation and voltage regulation, the circuit was tested using the Power-Z KT002 USB PD Analyzer, which facilitated:

  • Real-time monitoring of voltage and current outputs.
  • USB PD communication analysis to validate negotiation sequences.
  • Identification of power inefficiencies and optimization of conversion efficiency.
  • Verification of compliance with USB PD 3.0 standards.

Multiple testing iterations helped refine the system to deliver a stable 100W output while ensuring safe operation.

Integration of TPS65987 for USB Data Transfer

Since FUSB3307 handles power delivery but lacks USB 3.0 data transfer support, the TPS65987 USB-C PD controller was integrated to enable simultaneous power and data transmission.

Why TPS65987?

  • Supports 100W USB PD while enabling high-speed data transfer.
  • Integrates power path management for stable voltage regulation.
  • Supports Alternate Modes, such as DisplayPort over USB-C.
  • Provides flexibility for configuring USB functionality.

Testing with TPS65987EVM, TI CC Studio, and Technical Support

To validate functionality, the TI TPS65987EVM evaluation module was used and configured via TI Code Composer Studio (CC Studio). This setup enabled:

  • Fine-tuning of PD settings to optimize power delivery.
  • USB 3.0 data transmission testing for stable data transfer.
  • Alternate mode setup for video output through USB-C.
    During development, various configuration challenges were encountered with the TPS65987. Support was sought from TI Support and the TI Technical Forum, where insights were provided to resolve firmware and configuration-related issues. After thorough testing and debugging, the TPS65987 was successfully implemented, making it an ideal solution for single-cable USB-C applications.

PCBA Photos

4 -Layer PCB