USB Type-C™ and USB PD Demystified
Presenter: Greg Gosciniak
Affiliation: Applications Engineer
Content Overview
- USB Type-C and USB Power Delivery benefits
- USB Type-C overview
- ST Offer
- Evaluation Tools
The Re-evolution of USB
USB has evolved from a data interface capable of supplying limited power to a primary provider of power with a data interface.
Key advancements include:
- USB Type-C [?]: A new reversible & thinner connector.
- Power Delivery [⚡]: Supports up to 100W.
- Alternate Mode [?]: Enables protocols like Display Port, HDMI, VGA, Ethernet.
- USB IF [®]: Promotes standards and interoperability.
- Speed: Increased speed with USB 3.1 Gen 2 (10 Gbps).
USB Type-C and USB Power Delivery
Modifying the ecosystem, enabling new scenarios.
USB Type-C: One port to rule them all
A diagram illustrates USB Type-C's versatility, showing a single port connecting various devices:
- Tablet: Dual role / charging.
- Laptop: Alternate mode on dock connector, charging / data.
- External Display: Display power.
- System Power: Up to 100W.
- Audio Device: Audio connection.
- Smartphone: Charging / Data.
USB Global Evolution
STMicroelectronics is a board member of USB-IF and a promoter of USB 2.0 & USB 3.0.
A timeline shows the evolution of USB connectors and capabilities:
- Connectors: Mini-B (2000), Micro-B (2007), Micro-B USB3.0 (2010), and Type-C (2014).
- Power Delivery: Evolved from Battery Charging v1.0 (2007) to v1.2 (2010) and Power Delivery v1.0 (2012), v2.0 (2014), v3.0 (2016).
- Data/Protocol: Advanced from USB 2.0 (2000) to USB 3.0 (2008) and USB 3.1 (2013) with speeds up to 10 Gbps.
Learn more at usb.org/developers/powerdelivery/.
USB Type-C Pin-Out Functions
Receptacle and Plug
The USB Type-C receptacle and plug pinouts are detailed. The receptacle has pins A1-A12 and B1-B12, including GND, TX/RX pairs, VBUS, CC1, CC2, D+/D-, and SBU pins. The plug mirrors this configuration.
Key Functions:
- CC1 and CC2 Pins: Used in connection discovery, configuration, and management.
- Cable Wiring: A standard USB Type-C cable uses one CC wire for orientation, with the other repurposed as VCONN for powering electronics.
- Data Paths: Includes High Speed Data Path (RX/TX for USB 3.1 or Alternate Mode), USB 2.0 Interface, Cable Bus Power (5V-20V), Sideband use, and Configuration Channel.
Host to Device Connection
This diagram explains the connection process between a Host (DFP) and a Device (UFP):
- Initial State: VBUS is not powered (cold socket).
- Insertion Detect: The Configuration Channel (CC pin) determines plug orientation. The Host is identified by a pull-up resistor on its CC pin, and the Device by a pull-down resistor.
- Connection Established: After a successful connection, VBUS is supplied, and VCONN is provided to the unconnected CC pin.
- Optional Modes: USB PD, Alternate, or Accessory modes can be optionally supported.
USB-PD 2.0(v1.2) & 3.0 Power Rules
PDO: Power Data Object (Voltage, Current)
The graph illustrates USB PD 2.0/3.0 power rules, showing current (A) versus source power rating (W) for different voltage levels (5V, 9V, 15V, 20V). The table provides specific current values for given power ranges, with notes on 5A cable requirements.
| PD Power (W) | Current (A) at 5V | Current (A) at 9V | Current (A) at 15V | Current (A) at 20V |
|---|---|---|---|---|
| 0.5 ≤ x ≤ 15 | x ÷ 5 | - | - | - |
| 15 < x ≤ 27 | 3 | x ÷ 9 | - | - |
| 27 < x ≤ 45 | 3 | 3 | x ÷ 15 | - |
| 45 < x ≤ 60 | 3 | 3 | 3 | x ÷ 20 |
| 60 < x ≤ 100 | 3 | 3 | 3 | x ÷ 20 (*) |
(*) Requires a 5A cable.
What to expect?
USB-C represents a huge, yet fragmented market.
The document projects over 2 billion USB-C units to ship in 2019, representing 40% of total units, based on IHS data from December 2015.
USB Type-C and USB Power Delivery-enabled subsystems
ST Chipset offers a flexible USB Type-C PD ecosystem.
This includes scalable offers from STM32 MCUs to hard-coded solutions for USB PD controllers and Type-C interfaces. Products cater to various applications like Tablets, Notebooks, Docking Stations, TV/Displays, and Set-top boxes, featuring SuperSpeed switches, USB 3.x/2.0, SBU, Dp/Dn, Protections, CC lines, and VBUS. STSAFE secure elements are also available for authentication.
USB Type-C and USB Power Delivery AC / DC converters
ST Chipsets for AC/DC converters provide ultra-low standby and compact power supplies. They feature high efficiency and low EMI design, with a wide range of Power MOSFETs offering reduced switching losses and simplified design.
ST Offer
Hard-Coded USB Type-C and USB PD Controllers
STUSB Family: from USB Type-C Interface to 100% HW Power Delivery Controllers
| STUSB1600 | STUSB1602 | STUSB47xx | |
|---|---|---|---|
| USB Type-C | USB Type-C interface | USB Type-C controller with PD PHY and BMC driver | - |
| Power Delivery | Less than 15W | - | Power Delivery controller Provider only |
| Alternate Mode | 5W to 100W | - | - |
Type-C & USB PD Controllers Certified Solutions
ST offers flexibility to designers for optimizing stack partitioning and BOM.
The architecture involves MCUs (STM32) and STUSB controllers (STUSB1600, STUSB1602, STUSB47) managing the USB PD stack, including digital functions, protocol layers, analog PHYs, and high voltage protections. ST provides firmware solutions (X-CUBE-USB-PD) and integrated hardware.
Key ST Products:
- STUSB1600: Standalone Type-C interface up to 15W.
- STUSB1602: Type-C PD Controller with PD PHY and BMC driver, suitable for DRP/DFP/UFP applications.
- STUSB4700: Full HW solution optimized for AC adapters (1 Port Provider).
STUSB1600 Features
USB Type-C controller Source / Sink / DRP
Key features include:
- Transition any USB Type-A/Micro-B to USB Type-C.
- Performs USB Type-C detection including port attach & cable orientation.
- Supports legacy, 1.5A & 3A USB Type-C charging profiles.
- Embeds: VCONN power switch (OVP,OCP,OTP), Vbus Monitoring & Discharge Path, Dead Battery Support, PMOS Gate drivers, High Voltage Protections (CC pins & Vbus).
STUSB4700 Features
Autonomous Type-C & USB PD controller
Key features include:
- Full HW USB-PD stack for safe USB PD r2.0 negotiation.
- Single Role, Provider Only (Source).
- Performs USB Type-C detection including port attach & cable orientation.
- Establishes Safe & valid Host to Device Connection.
- Offers up to 5 programmable PDOs.
- Offers very low power consumption.
- Embeds: Vbus Monitoring & Discharge Path, PMOS Gate drivers, High Voltage Protections (CC pins & Vbus).
STUSB4700 key differentiators
| FEATURE | BENEFIT |
|---|---|
| USB IF Certified silicon | Proven solution |
| Hard-wired | NO NEED FOR MCU, Robust / Predictive |
| Low Power consumption | Contribution to Energy-saving Standards |
| CC Short to Vbus protection (CC pins protected up to 22V) | Safe for users & devices |
| Wide Supply Voltage range [3V; 22V] | No external LDO required – Low BOM cost |
| High BOM Integration | Contribution to Power Density |
| Internal NVM | Easy customisation – Plug & PLAY, NO Software know-how required |
STUSB4700 Layout
High Integration/PCB Area Saving
Details on PCB layout for USB PD - Fly Back Secondary side, including class 5 PCB requirements and clearance/track width.
STUSB4700 vs MCU-Based Solutions in Power Supply
Comparing STUSB4700 with MCU-Based Solutions:
- DC-DC Requirement: STUSB47 is powered directly on VBUS (4-22V), unlike MCU-based solutions needing a dedicated DC-DC for 5V input.
- Power Consumption: STUSB47 consumes significantly less power (0.80mA, 0.05mA with no load) compared to an MCU (~7.5mA).
- Protections: STUSB47 integrates HV protections (22V on CC pins, 28V on other HV pins), discharge path, and gate drivers, reducing the need for external components.
MCU-based solutions are NOT effective for First Default protection.
STUSB1602 Features
Type-C & USB PD controller DRP/Source/sink
Key features include:
- Integrates the USB PD r2.0 PHY + BMC encoding.
- Compatible with USB PD r3.0.
- Acts as a companion chip to EC for USB Type-C port management.
- Performs USB Type-C detection including port attach & cable orientation.
- Embeds: VCONN power switch (OVP,OCP,OTP), Vbus Monitoring & Discharge Path, Dead Battery Support, PMOS Gate drivers, High Voltage Protections (CC pins & Vbus).
- Solves Security & safety concerns.
STUSB1602 vs USB PD r3.0 IC compatibility versus standard
The STUSB1602 is compliant with PD r3.0 core features and supports various optional application-specific features.
| Feature | Compatibility | Applications |
|---|---|---|
| PPS - VBUS min down to 3V instead of 5V | 3.0 (optional Application specific) | Smartphone Chargers |
| Long messaging (260 bytes)+extended msg chunck | 3.0 (optional Application specific) | Authentication / Firmware Update applications |
| Fast Role SWAP without discharge (DRP only) | 3.0 (core) | Docking Stations, Computer |
| Battery messaging | 3.0 (core) | Required for battery operated systems |
| Additional Alerts, capabilities, status | 3.0 (core) | Support for IEC 63002 power supply standards |
| SVDM update (v2.0) | 3.0 (core) | |
| Non supported commands, EMCA communication | NOT SUPPORTED | |
| Collision avoidance mechanism (Enhanced) | NOT SUPPORTED | |
| Incremental Power Rules | 2.0 (core) | |
| Role SWAP Collision Avoidance | 2.0 (core) |
USB PD HW/SW partitioning with STUSB1602
This section details the hardware/software partitioning for USB PD using the STUSB1602.
- USB PD Stack: Includes System Policy Manager, Device Policy Manager, Policy Engine, Protocol layer, 4b5b, CRC, SoP, BMC encoder, USB PD RX/TX analog PHY, Type-C Interface, and High Voltage Protections.
- MCU Role: Manages the USB PD stack, handling Type-C features (port connection, dead battery, cable orientation, VCONN supply) and system/application features (power path, voltage transitions, VBUS monitoring, protections).
- STUSB1602 Role: Integrates PD features like packet conditioning and BMC encoding/decoding, and provides system/application features such as VBUS gate drivers, discharge path, monitoring, and protections.
STUSB1602 Suitable Applications
The STUSB1602 is suitable for applications in either PD r2.0 or r3.0:
- All SINK applications: Including authentication (PDr3.0 option) and long messaging (PDr3.0).
- SOURCE applications: Conventional chargers and AC/DC adapters, PPS fast chargers (under evaluation), DC/DC converters.
- DUAL ROLE applications: All single port-supplied devices (smartphone, tablet), multi-port applications not requiring Fast Role SWAP, Set-top-boxes, TVs.
System and USB PD Controller Block Diagram
A block diagram illustrates a battery charger/DC/DC power path using the STUSB1602. It shows the SRC and SINK paths, VBUS, VDD, VSYS, and the interaction between the MCU (via I2C/SPI) and the STUSB1602 for USB PD control, Type-C features, and system/application features like VBUS monitoring, discharge path, and protections. The USB Type-C receptacle pinout is also detailed.
Integration Comparison
Comparison of STUSB1600, STUSB1602, and STUSB47 with external components:
| Feature | STUSB1600 Type-C Only (< 15W) | STUSB1602 (1 port – DRP) | STUSB47 (1 port Provider Only) |
|---|---|---|---|
| Vconn Switch | External Components | Integrated | Integrated |
| Dead Battery | External Components | Integrated | Integrated |
| CC HV Protect | External Components | Integrated | Integrated |
| Discharge path | External Components | Integrated | Integrated |
| Vbus gate Driver | External Components | Integrated | Integrated |
| Vbus Monitor | External Components | Integrated | Integrated |
| Type-C PD phy | STM32F0 + FW | Integrated | Integrated |
| PD stack | STM32F0 + FW | Integrated | Integrated |
| Current sensing | External Components | Integrated | Integrated |
Benefits of STUSB16xx: Support Active cable & mandatory for USB3.1 & >60W charging; Mandatory for Battery powered consumer devices; Overvoltage protections on CC pins (up to 24V); High voltage discharge/switch; Fast overvoltage detection; BMC & Rx Tx drivers, Configurable Start-up profiles, Wide Supply voltage range (3 to 5.5V).
Evaluation Tools
ST offers various evaluation tools and demo kits for its USB Type-C and PD controllers.
STUSB4700 DEMO - 36W Fly-back
Status: ORDER CODE: - , AVAILABILITY: On Request (limited quantities)
Target Applications: Universal or OEM Power Supplies, AC adapters for Computer, Tablets, STB etc.
Key ST products: IPC: PWM controller (STCH02), IPC: CV controller (TLVH431), GPA: PD controller (STUSB4700), IPAD: ESD protection (ESDA25L- SMM4F24A).
Description: AC/DC 36W Fly-back topology with CV, Number of PDO: #3, Voltage Select: Digital Output (Vsel_PDO), Fixed current.
STUSB4700 DEMO - 45W Fly-back
Status: AVAILABILITY: On Request (limited quantities)
Target Applications: Universal or OEM Power Supplies, AC adapters for Computer, Tablets, STB etc.
Key ST products: USB PD controller (STUSB4700), PWM controller (STCH02), CV controller (TLVH431AICT), ESD protection (ESDA25L- SMM4F24A).
Description: AC/DC 45W Fly-back topology with CV, Number of PDO: #3, Voltage Select: Digital Output (Vsel_PDO), Fixed current.
STUSB4700 EVALUATION - 60W Buck DC/DC converter
Status: ORDER CODE: STEVAL-4710-BUCK, AVAILABILITY: yes (tbc)
Target Applications: Computer, Power Hub, Accessories, TV, Display, Set Top Box, Gaming, Industrial.
Key ST products: IPC: DC/DC (ST1S14), GPA: PD controller (STUSB4700), IPAD: ESD protection (ESDA25L- SMM4F24A).
Description: DC/DC 60W Buck Topology, Number of PDO: #5, Voltage Select: Analog Output (VVAR), Current regulation: ST1S14.
STUSB1600 EVALUATION – Single Port Xpansion board
Status: ORDER CODE: X-NUCLEO-1600, AVAILABILITY: yes (tbc)
Target Applications: Computer, Power Hub, Accessories, TV, Display, Set Top Box, Gaming, Industrial.
Key ST products: GPA: Type-C controller (STUSB1600), IPAD: ESD protection (ESDA25L- SMM4F24A).
Optional NUCLEO board: MCD: MCU (STM32F072 - NUCLEO).
Description: STUSB1600 evaluation environment, suitable for SINK, SOURCE, DRP. Supports Dead Battery, Vconn, Vsys, VDD. Can run without Nucleo board (requires GUI access to STUSB1600 I2C interface).
STUSB1602 DEVELOPMENT – Dual Port STM32 Nucleo Pack
Status: ORDER CODE: P-NUCLEO-USB002, AVAILABILITY: yes (tbc)
Target Applications: Computer, Power Hub, Accessories, TV, Display, Set Top Box, Gaming, Industrial.
Key ST products: GPA: PD controller (2 x STUSB1602), IPAD: ESD protection (ESDA25L- SMM4F24A), MCD: MCU (STM32F072 - NUCLEO), SMD: Authentication IC (STSAFE).
Description: STM32 + STUSB1602 evaluation environment. Includes Type-C cable, Dual Port DRP system, Dead Battery Support, Vconn, Vsys, VDD support. Requires dedicated SW environment.
Key messages
- ST is strongly involved in USB Type-C & PD controllers, being a member of the USB-IF consortium and USB PD working groups.
- Certified Solutions Available:
- Type-C only for easy & Safe transition from Std-A to Type-C using STUSB1600.
- USB PD & Type-C Autonomous full HW controller for Provider Only applications using STUSB4700.
- USB PD & Type-C controller for DRP/DFP/UFP applications as a companion to Embedded Controllers using STUSB1602 supporting USB PD r3.0.
- Towards more features:
- Using Gen2 USB PD & Type-C Autonomous full HW controller supporting USB PD r3.0.
- Using Gen2 TCPC controller including HV analog Front end.
- Using a new family of Power switches for Type-C & PD applications.
- Using STUSB1600Y, STUSB4700Y, STUSB1602Y for Automotive grade devices.
