PROTECTION SOLUTIONS

Four-Line TVS Array Protects High-Speed Interfaces

The ESD5V3U4U-HDMI from Infineon is a Transient Voltage Suppression (TVS) diode array that combines electrostatic discharge protection with ultra-low capacitance for high-speed signal integrity and permits uncomplicated PCB layout.



The device is designed to protect high-speed interfaces, such as HDMI1.3, DisplayPort, USB 3.0, FireWire and MicroSD, from ElectroStatic Discharge (ESD) generated by end users. Applications include digital televisions, DVD/Blu-ray players and recorders, game consoles, digital set top boxes, LCD monitors and mobile communications equipment.

The ESD5V3U4U-HDMI is qualified to withstand ESD strikes of up to 20kV (contact and air discharge), exceeding the standards set in IEC61000-4-2 level 4. According to tests performed at 8kV contact discharge, the device offers at least 40% better clamping performance than alternative solutions, both in terms of response time and clamping voltage.

One of the most critical tests in HDMI certification is TDR (Time Domain Reflectometry) characterisation for HD-TV use. Even a small amount of added capacitance on an HDMI port can cause a drop in the impedance of the differential pair, leading in turn to heavily attenuated signals and consequently to certification compliance issues.

The use of higher capacitance protection solutions necessitates modifications to the PCB layout to compensate for these effects and to meet the TDR specification window of 100Ω ±15% and the more stringent ±10% value for the HDMI load.

In contrast, the ESD5V3U4U-HDMI has a maximum capacitance of 0.4pF (line to ground) over a frequency range of 1MHz to beyond 3GHz, eliminating the need for compensation structures on the PCB.

The device also reduces system size and complexity, since a single ESD5V3U4U-HDMI array can protect four high-speed data lines, with a potential board space saving of up to 50% in comparison with ceramic protection devices typically offered in 0402 case sizes.

Board layout is simplified further by the fact that the array’s TSLP-9 package has an interconnect spacing of 0.5mm. This is identical to the pin spacing in HDMI 1.3 and DisplayPort connectors, allowing the array to be positioned directly on top of two differential microstrip line pairs, without the need for stubs or bends in the PCB traces.

Features

• Four-line TVS diode array
• Up to 20kV ESD absorption capability
  • Exceeds IEC61000-4-2 level 4
• 0.4pF maximum line-to-ground capacitance
• Fast response time
• Low clamping voltage
• TSLP-9 package
  • Can be located directly above standard connector pins
• Up to 50% board space saving

Applications

• ESD protection for high-speed interfaces:
  • HDMI 1.3
  • DisplayPort
  • USB 3.0
  • FireWire
  • MicroSD
• Digital televisions
• DVD/Blu-ray players and recorders
• Game consoles
• Digital set top boxes
• LCD monitors
• Mobile communications equipment

For further information, including the Datasheet and Application Note for the ESD5V3U4U-HDMI, please click here