TECH BRIEF ESD Protection IEEE 1394 Data Lines 1394a (400 Mbps) and the upcom- ing IEEE 1394b (800 - 1,600 Mbps), suppressors with extremely low capacitance levels should be used. Suppressors with high capacitance can affect the data stream by IEEE 1394 Product (card or box) Circuit Board distorting the data waveforms PWR IEEE 1394 Controller GND Littelfuse offers PulseGuard? ESD suppressors as a solution for IEEE 1394 data line ESD protection. These products are surface mount devices with 0.050 pF of capaci- tance. They will provide ESD protection and maintain the Data integrity of the data signals. Figure 1. Simple IEEE1394 circuit diagram (ESD suppressors protect the data lines which have exposure to the outside world. The 1394 protocol uses 4 high-speed data lines). Background will propagate down the data lines toward the integrated circuitry. Specifically, the IC of concern is the IEEE 1394 Controller. Without sufficient protection, the Controller chip can be rendered inoperable. Examples of IEEE 1394 products which can benefit from ESD protection include: IEEE 1394 products (PCI adapter cards, hubs/routers, etc.) can be susceptible to ESD events when the cable is disconnected from the data port. The ESD pulse can be introduced directly into the open port, or into the disconnected end of the cable. Either way, the inte- grated circuitry that controls the IEEE 1394 functionality can be compromised. ? Computers (desktops and laptops) ? PCI adapter cards ? Repeaters and hubs ? External hard drives ? Digital video recorders ? Digital still cameras ? Recordable CD