Product Pages: 
SMA6J12
SMBJ12
Developed using a new planar technology, the new 600W SMA6J series
of Transils have a maximum junction temperature of 175°C. These
devices provide a higher safety margin in SMPS and other applications,
while low leakage current makes them suitable for portable equipment.
The VCL for 8/20µs surges is compliant with the
most-used standard in the industry: the IEC 61000-4-4.
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Protection devices are designed to protect sensitive equipment from
power surges. But to really understand the level of protection provided,
one must be aware of the various surge standards. In the best standards,
surge models are provided, as in the case of the much-used IEC 61000
standard. At the same time, while protection devices are expected
to protect more sensitive ICs from standard power surges, they should
not disturb the operation of the application. To this end, protection
devices must not impinge on the electrical parameters of the protected
IC, should be compatible with the operating temperature of the applications
and use a minimum of board space.
Some markets, such as telecom or automotive, where surges are defined
according to lightning strikes and load dumps, use specifications
defined specifically for their needs. But for the vast majority
of products (most industrial, consumer and computer applications),
the IEC 61000-4-4 specification is appropriate and applicable. It
specifies a 8/20µs surge with various levels depending on
environment and applications. The SMA6J series are all specified
for 10/1000µs and 8/20µs surges. The maximum clamping
voltage (VCL) has been improved by up to 9% as compared
with the standard SMBJ series.
| VCL
Comparison With Standard SMBJ Series |
|
|
|
8/20µS |
10/1000µS |
VRM
[V]
|
VCL
[V]
|
IPP
[A]
|
VCL
[V]
|
IPP
[A]
|
| |
12 |
23.5
|
157
|
18.8 |
31
|
|
19.9 |
| Maximum Junction
Temperature |
Maximum junction temperature requirements vary depending on the
application. The most demanding requirements are for applications
such as switch mode power supplies (SMPS), where products must withstand
up to 150°C. The SMA6J series are the first specified at Tjmax
= 175°C. Typically, this gives at least a 25°C safety margin
for SMPS applications, where ST rectifiers are already rated at
175°C. For most of the applications working around 125°C,
this new series doubles the safety margin, providing a better reliability
of the equipment.
Safety margin increase on temperature
Thanks to their high temperature capability, maximum leakage current
has been decreased from 1µA to 0.2µA at 25°C, and
is now also specified at 1µA max at 85°C. For other temperatures,
IR = f(Tj) is given in the datasheet and shows a typical leakage
current of about 5µA at Tj = 175°C.
| SMA Package Size
Comparison With Competitors |
| |
Other |
ST
|
| Length |
5.6mm |
5.35mm |
Width |
3.95mm |
2.9mm |
Height |
2.65mm |
2.23mm |
PCB
area |
22mm2 |
15mm2 |
|
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