Single-chip Type-C to DP Solution Based on Hynetek HUSB252

With the rapid development of consumer electronics technology, thin and light has become a new trend in laptop design. In order to realize thin and light design, more and more laptops abandon the traditional USB-A, HDMI, DisplayPort and RJ45 ports and turn to the full-featured Type-C interface. This full-featured Type-C port not only enables charging and data transmission, but also can be used for video signal transmission.

Despite the widespread adoption of full-featured Type-C ports on laptops, a significant number of monitors and projectors still only offer traditional HDMI and DP (DisplayPort) interfaces. This leads to incompatibility between devices and prevents direct connection for screen mirroring...

USB Type-C Plug Pinout

DisplayPort Pinout

To address this pain point, Type-C to DP converters have been developed.

The following will introduce a single-chip Type-C to DP solution based on the Hynetek HUSB252.

The HUSB252 is designed for a USB Type-C DRP product. It can support up to multiple PDOs with programmable voltage and current for different applications, such as PPS PDOs. All of PDOs are fully compliant with USB PD 3.1 Specification Rev.1.8. Besides, the HUSB252 implements DPDM charging protocols. Both D+ and D- pins can be configured to support QC2.0, QC3.0, AFC, FCP, SCP, UFCS and divider 3 mode which provide excellent compatibility for the legacy devices. It integrates an GATE driver to enable the VBUS from VIN to protect the devices connected with Type-C connector. The high voltage tolerance and protections at CC1, CC2, D+ and D- pins provide more reliability for the system.

FEATURES

• USB Type-C DRP with PD protocol Supported

    – Compliant with USB Type-C Specification Reversion 2.1 

    – Compliant with USB PD Specification Reversion 3.1 

• Integrated VCONN Power for eMarker Detection

• Integrated high voltage driver for N-MOSFET

• Multiple DPDM Charging Protocols Implemented

    – BC1.2 DCP and Divider 3 

    – QC2.0, QC3.0, AFC, FCP, SCP, UFCS 

• Up to 30 V Maximum Voltage Rating at USB Type-C Connector Pins

• Integrated dead battery function for power requesting as SINK

• Programmable Constant Voltage and Constant Current Control

• Fault Protections including Over-Voltage ※ Protection, Over-Current Protection, Short Circuitry Protection, Over-Temperature Protection, Under-Voltage Protection, CC Over- Voltage Protection, DPDM Over-Voltage Protection, Thermal Shut Down

• Integrated MCU with MTP Memory

• ±1500 V HBM ESD Rating for all of Type-C Connector Pins

HUSB252 Type-C to DP Solution (C2DP Adapter)

HUSB252 C2DP Program Circuit Diagram and Demo Board

The HUSB252 C2DP Adapter is a minimalist single-chip solution. One end of this adapter features a Type-C plug, designed to connect to the Type-C receptacle on laptops, smartphones, and other DP Source devices; the other end is a DP receptacle for connecting a DP cable, which then connects to a display. When in use, the user inserts the Type-C plug of the HUSB252 C2DP Adapter into the laptop and uses a standard DP cable to connect the HUSB252 C2DP Adapter to the display, thereby achieving screen mirroring.

In this solution, the HUSB252 serves as a Sink + UFP_D. It communicates with the laptop via the CC pin on the Type-C plug side to complete PD power negotiation, obtaining 5V from Vbus to power the system of the conversion board. Following this, it completes communication for DP Alternate Mode, switching the laptop into DP Alternate Mode and configuring the data link for internal video signal output, ensuring proper transmission of video signals to the display.

DP Alternate Mode communication

On the DP receptacle side, the HUSB252 monitors the status of the HPD (Hot Plug Detection) pin to determine the connection status of the external display and reports the real-time HPD signal state to the laptop via PD messages. Once the laptop's DP Source receives confirmation that a display is connected, it proceeds to complete the DP protocol communication over the SBU/AUX channel and then outputs the video data stream, thereby completing the screen mirroring action.

Using this Type-C to DP converter successfully mirrors the screen to the display

Solution Highlights:

1. The solution requires only a single HUSB252 chip and a few peripheral components to complete the design.

2. The HUSB252 integrates an internal Dead Battery Rd resistor, enabling connection establishment with the PD Source even in a dead battery state, prompting the PD Source to provide 5V Vbus for system power supply.

3. An LDO (Low Dropout Regulator) is integrated within the HUSB252, capable of converting the 5V Vbus power supply into the necessary voltage source for the chip, thus eliminating the need for additional power circuit design for the customer's system.

4. The Vbus, VIN, and CC pins of the HUSB252 can withstand high voltages, and the CC pin features Vbus short-circuit protection, removing the need for an external port protection device and ensuring reliable system operation.