Ultra-miniature device offers 8kV protection to high-speed signal lines

May 31, 2013 // By EDN
A 2-channel ESD protection diode removes damaging transients from Full-Speed USB 2.0 and RF interfaces.

Toshiba Electronics Europe (TEE) has extended its line-up of low-capacitance ESD (electrostatic discharge) protection devices with the DF4D6.8UG. The DF4D6.8UG comes in a compact 4pin Wafer-Level-Chip-Scale Package (WCSP4B) and offers ESD protection for dual high-speed data lines while minimising board space. The device targets applications that are increasingly sensitive to ESD events due to reduced feature sizes and working voltages in the system, for example microUSB 2.0 interfaces in smartphones.

It is essential to minimise the load that is added to the data line with any kind of ESD protection measure when considering signal integrity, especially with high-speed USB 2.0 data. The DF4D6.8UG diode, which has a typical capacitance of 1.3 pF with a difference of 0.02 pF between the different lines, ensures maximum protection level while maintaining signal quality. Guaranteed ESD immunity is +/-8kV contact discharge according to IEC61000-4-2.

The DF4D6.8UG has a minimum reverse breakdown voltage of 6V and offers a typical clamp voltage of 10V. There is no significant load on the data line owing to a maximum reverse current of 0.1 µA, while a dynamic resistance of typical 0.7 Ω ensures a high protection level in case of an ESD event. With a combination of the two line protection diodes in a series configuration, the DF4D6.8UG can also be used in applications such as protection of RF antenna interfaces.

Toshiba Electronics Europe, www.toshiba-components.com