Application Note

Description

Since most of the base stations are built on mountains and isolated locations in the suburbs, they are extremely vulnerable to lightning strikes. Most of their DC power supply modules are based on (DC-48V): in applications, they are connected in series with discharge tubes (GDT) with large current capacity. Use and adopt high-current SHC products to clamp the overvoltage within the tolerance range of the subsequent circuit with a very fast response speed, and because the SHC single branch has a large flow rate, the number of parallel connections can be reduced to reduce the risk of inconsistent operating points.
protection gesture

Instructions

Network port Surge(SHN)

DC/DC
Surge(SHC)

1 of 3
DC/DC Surge(SHC)

DC/DC
Surge(SHC)

2 of 3
AC/DC Surge(SHV)

DC/DC
Surge(SHC)

3 of 3
Applicable series

Application

Type of surge Surge EFT
Application SHC SHN SHV MLC MLA
Standard IEC61000-4-5 IEC61000-4-4

Product Description

SFI has developed the SHC series of multi-functional overvoltage protectors for communication base stations. SHC itself has a highly non-linear curve. At the same time, SHC provides "ultra-small size SMD chip" packaging. The extremely small size can suppress a large current up to 20KA and has "excellent high temperature characteristics". Compared with the MOV currently used in the market For the "disadvantage" of "easy to deteriorate", SHC is the best choice for overvoltage components used in communication base stations.

feature comparison

feature comparison

Comparison

SFI

solutions SHC Series

1.SMD package (0805~4032).
2.Specially designed for low-voltage related electronic controllers.
3.Low suppression voltage.
4.Extremely low leakage current (<10μA).
5.The response speed is faster than the plug-in MOV (<1ns).
6.High non-linear index α Reaching (above 25).
7.Passed IEC61000-4-5 testing.
8.Good impact ability exceeding 10 times.
9.Compliant with RoHS requirements and lead-free tin furnace.
10.Non polar bidirectional action.
11.Extremely wide operating temperature -55°C to +125°C.
12.Avoiding the issue of TVS high-temperature performance degradation.
13.Space saving and competitive advantage.

Other solutions

MOV (Motel Oxide Varistor)

1.Large size of plug-in packaging (5 Å~14 Å).
2.High suppression voltage.
3.Large leakage current (<50μA).
4.Slow reaction speed (>100ns).
5.Severe deterioration phenomenon.
6.Failure modes may lead to combustion phenomena.

MLV(Mutilayer Varistor)

1.SMD package has insufficient flow rate (1200A).
2.The suppression voltage is higher than SHC.
3.Less resistant to continuous impact.
4.Not resistant to high temperature environment 125℃.

Application line

Application Circuit

AC Power single phase L-L surge protection

AC Power single phase L-L&L-G surge protection

PHY side for CM mode surge Protection(two pairs)

DC Power for Surge Protection

AC Power single phase L-L surge protection
AC Power single phase L-L&L-G surge protection
PHY side for CM mode surge Protection(two pairs)
DC Power for Surge Protection
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