Menlo Park, Calif. Tyco Electronics has introduced a reference layout for electrostatic discharge (ESD) and over-current protection for HDMI 1.3 interfaces. The reference layout uses Tyco's low-capacitance (0.25 pF signal-to-ground) PESD protection devices, and space-effective component placement and routing to help protect against ESD events and optimize board space. The reference layout, said to be the industry's first based on passive protection devices, also includes an optional over-current protection on the +5-V rail.
The HDMI 1.3 standard doubles the previous HDMI data rate to 3.4 Gbits/s per differential signal pair. With high data transmission rates, low capacitance and good board design are crucial to provide adequate signal integrity, said Tyco. The reference layout for HDMI 1.3 was developed in conjunction with Efficere, Inc., a leader in high-speed interface design and test, to ensure the reference layout meets or exceeds the HDMI 1.3 specifications for operation at 3.4 Gbits/s for impedance (TDR), data eye, and far-end crosstalk.
The bi-directional PESD0603 or PESD0402 devices are configured in a very small space behind the HDMI connector and help designers meet the IEC 61000-4-2 standard for ESD protection (+/-15 kV for air, +/-8 kV for contact). The PESD devices are offered in EIA standard 0603 and 0402 sizes and can be used in various end applications including DisplayPort, WiMAX and cellular base stations, eSATA, and other high-speed data and analog interfaces.
In HDMI source devices such as DVD players, set-top boxes, computers and other HD sources, the specification requires that the transmitter interface's voltage rail include over-current protection to prevent short circuit or abnormally high current from damaging the source device. The protection layout includes optional over-current protection on the +5-V rail using the PolySwitch nanoSMD circuit protection device.
A white paper about the reference layout is available at: www.circuiprotection.com/hdmi.
Availability: The PESD0603, PESD0402, and PolySwitch nanoSMD devices are available in volume, and are compatible with standard surface-mount and reflow installation procedures.
Tyco Electronics, 1-800-227-7040, www.circuitprotection.com