APPLICATION NOTE
USB0403
thru
USB0424C
The USB04 Series are TVS arrays designed to protect I/O or data lines from the damaging effects of ESD and EFT. This product series provides
both unidirectional and bidirectional protection, with a surge capability of 350 Watts PPP per line for an 8/20µs waveform and ESD protection > 40kV.
UNIDIRECTIONAL COMMON-MODE CONFIGURATION (Figure 1)
The two USB04 Series devices provide protection in a common-mode
configuration as depicted in Figure 1.
Circuit connectivity is as follows:
✔ TVS Device 1: Line 1(D+) is connected to Pins 2 & 3.
✔ TVS Device 2: Line 2(D-) is connected to Pins 2 & 3.
✔ Both TVS Devices: Pins 1 & 4 connected to ground.
Figure 1 - Unidirectional Configuration (Two TVS Devices)
Common-Mode USB Protection
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GND
SOLDER PAD
2
3
2
3
USB IC
D+
D-
BIDIRECTIONAL DIFFERENTIAL-MODE CONFIGURATION (Figure 2)
The USB04xxC Series provides protection in a differential-mode configuration
as depicted in Figure 2.
Circuit connectivity is as follows:
✔ Line 1(RX) is connected to Pins 1 & 4.
✔ Line 2(TX) is connected to Pins 2 & 3.
CIRCUIT BOARD LAYOUT RECOMMENDATIONS
Circuit board layout is critical for Electromagnetic
R
Compatibility (EMC) protection. The following
guidelines are recommended:
✔ The protection device should be placed near the
R
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.
✔ 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.
Figure 2 - Bidirectional Configuration
Differential-Mode Ethernet Protection
RX
1
4
2
3
TX
05205.R0 4/05
4
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