SLVU2.8-4_05 Datasheet, PDF (4/5 Pages) Protek Devices – ULTRA LOW CAPACITANCE TVS ARRAY

SLVU2.8-4
APPLICATION NOTE
Electronic equipment is susceptible to damage caused by Electrostatic Discharge (ESD), Electrical Fast Transients (EFT), and tertiary lightning
effects. Knowing that equipment can be damaged, the SLVU2.8-4 was designed to provide the level of protection required to safe guard sensitive
equipment. This product can be used in different configurations to provide a level of protection to meet unidirectional line requirements as well as
bidirectional requirements either in a common-mode or differential-mode configuration.
UNIDIRECTIONAL COMMON-MODE CONFIGURATION (Figure 1)
Figure 1. Unidirectional Common-Mode Protection
The SLVU2.8-4 provides up to four lines of protection in a common-mode configuration as
depicted in figure 1.
Circuit connectivity is as follows:
✔ Line 1 is connected to Pin 1
✔ Line 2 is connected to Pin 7
✔ Line 3 is connected to Pin 3
✔ Line 4 is connected to Pin 5
✔ Pins 2, 4, 7 and 8 are connected to ground
BIDIRECTIONAL COMMON-MODE CONFIGURATION (Figure 2)
The SLVU2.8-4 provides up to two lines of protection in a common-mode configuration as
depicted in figure 1.
Circuit connectivity is as follows:
✔ Line 1 is connected to Pins 1 & 8
✔ Line 2 is connected to Pins 4 & 5
✔ Pins 2, 3, 6, and 7 are connected to ground
External diode to ground is a low capacitance
diode of less than 10pF
BIDIRECTIONAL DIFFERENTIAL-MODE CONFIGURATION (Figure 3)
The SLVU2.8-4 provides up to two-line pairs of protection in a differenital-mode configuration as
depicted in figure 1.
Circuit connectivity is as follows:
✔ Line Pair 1 is connected to Pins 1 & 2
✔ Line Pair 1 is connected to Pins 7 & 8
✔ Line Pair 2 is connected to Pins 3 & 4
✔ Line Pair 2 is connected to Pins 5 & 6
Figure 2. Bidirectional Common-Mode Protection
CIRCUIT BOARD LAYOUT RECOMMENDATIONS
Circuit board layout is critical for Electromagnetic
Compatibility (EMC) protection. The following
guidelines are recommended:
✔ The protection device should be placed near the
input terminals or connectors, the device will
divert the transient current immediately before it
can be coupled into the nearby traces.
✔ The path length between the TVS device and
the protected line should be minimized.
Figure 3. Bidirectional Differential-Mode Protection
✔ All conductive loops including power and ground
loops should be minimized.
✔ The transient current return path to ground
should be kept as short as possible to reduce
parasitic inductance.
✔ Ground planes should be used whenever
possible. For multilayer PCBs, use ground vias.
05142.R10 4/05
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