and class A for RE. Power supplies are normally tested
with resistive loads when certifying their performance
to these standards. This sometimes presents a
challenge to equipment designers in that once the
power supply is integrated with the test equipment,
the EMI profile will typically change, as other factors
(cabling, grounding, etc.) can change the overall system
performance to these standards. A power supply that
is designed to meet these standards with some level of
margin gives test equipment designers a better chance
of maintaining compliance in their equipment. This
minimizes development time and potential material
cost to make the end system compliant.
Test equipment operates in many environments–
production lines in factories around the world
(both testing other products, and in the
factories building the test equipment itself),
design engineering labs, research labs, etc.
Many remote environments present different
challenges to the equipment designer, as the
equipment must operate continuously and
reliably in all geographies and environments
the equipment is to be used. Unstable power
sources, noisy (electromagnetic) environments,
etc., can affect the operation of a power supply,
and therefore, the system that it is used within.
In order to provide the best protection against
external influences, compliance to the highest
levels of Electromagnetic Compatibility (EMC)
standards is needed. The typical standards
are IEC61000-4-x, with the “x” being one of
various numbers denoting a specific section
of the standard. Most power supplies comply
with various levels of certain sections of the
IEC61000 standard, the following being the
typical (figure 1).
IEC 61000- 4-2 defines levels of Electrostatic
Discharge (ESD) protection, using two different
testing methodologies. Contact discharge
involves discharging an ESD pulse directly from
the ESD test gun that is touching the Device
Under Test (DUT). Air discharge is the other,
where an ESD test gun is brought close to the
DUT until a discharge occurs.
• Levels 1 & 2 are reserved for equipment which
is installed in a controlled environment and in
the presence of anti-static materials.
• Level 3 is used for equipment which is
sparsely, but not continuously handled.
• Level 4 is required for any equipment which is
For test equipment which comes in contact with
operators regularly, level 4 (8kV contact, 15kV air)
would provide the best protection for all environments.
IEC61000- 4-5 relates to the immunity requirements,
test methods, and range of recommended test levels
Figure 1. IEC61000 section descriptions.
(All figures and images courtesy of SL Power).
Electrostatic discharge IEC61000- 4-2
RF Field Susceptibility IEC61000- 4-3
Electrical Fast Transients/Bursts IEC61000- 4-4
Surge Immunity IEC61000- 4-5
Conducted Disturbances induced by RF Fields IEC61000- 4-6
Power Frequency Magnetic Field Test IEC1000- 4-8
Voltage Interruptions, Dips, Sags & Surges IEC61000- 4-11
Now You Have a Choice!
Until now, the choices for temperature variable attenuators
were slim. Now you have a choice. introduces the AVX
series of thick film temperature variable attenuators. The
AVX series is a highly accurate, extremely robust family of
temperature variable attenuators that drop directly onto the
incumbent’s footprints. There is no need to change an
existing design to accommodate an alternate device.
AVX-1412WA06 AVX-0706SS12 AVX-0706SS20
The AVX Series have these features:
• Values from 1 dB to 10 dB
• Compensation curves from N3 to N10
• Surface mount or wire bond
• Single side or wraparound
• Nickel/tin or gold
• 6 GHz, 12. 4 GHz or 20 GHz
This is just the beginning. Contact us to learn more.
International Manufacturing Services, Inc.
50 Schoolhouse Lane, Portsmouth, RI USA 02871
...the compensation you deserve!