What is EMI? EMI (Electromagnetic Interference) is broadly defined as any unwanted electrical or...
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Transcript of What is EMI? EMI (Electromagnetic Interference) is broadly defined as any unwanted electrical or...
What is EMI?
EMI (Electromagnetic Interference) is broadly defined as any unwanted electrical or electromagnetic energy that causes undesirable responses, degraded performance, or failure in electronic equipment.
For our purposes we are usually concerned with radiated and conducted EMI in electronic equipment in command, control, information and communication systems.
A basic working definition
Sources of EMI and EMP
High frequency devices Electronics/computers Cell phones/radios Wireless/RF energy Microwave equipment Power lines Electric motors Electrostatic discharge (ESD) Lightning (LEMP) Nuclear event (HEMP) Others
Radiated and Conducted
Electromagnetic Compatibility (EMC)
In a perfect world, every electronic enclosure would have six (6) sides and be completely sealed or welded, with no holes or apertures, providing 100% electronic shielding and containment.
In the real world, electronic enclosures have doors or removable sides, switches, connectors, indicators and gauges, thru-bulkhead fittings, and other openings that need to be electrically “closed” via conductive shielding products and technologies
Glenair is in the EMC business!
EMC Technologies
Cable and wire shielding Grounding springs and pins Shielded boxes and cases Conductive platings Conductive gaskets EMI backshells Conduit solutions Capacitor and diode filter
devices
Delivering clean data streams, undistorted by EMI, requires a multi-disciplinary approach
What is a Filter Connector?
Filter connectors use internal capacitors and (optionally) inductors and diodes (for EMP applications) to “strip off” unwanted noise or transient voltages from the signal.
Types include tubular, planar array, chip on flex/board, EE seal and others
“Low-pass” filters attenuate high-frequency noise and allow low-frequency signals to pass
Each application environment dictates different capacitance values and cut-off frequencies to affect desired performance
Virtually any standard connector type can be outfitted with filtering technology
A basic working definition
Why Use a Filter Connector?
Easiest permanent EMI/EMP solution – designed to strip off conducted EMI before it passes through the device.
Variable capacitance from 500 pf to 50,000 pf Small package size – doesn’t consume PCB real estate. Can easily replace existing non-filtered connector. Mates with standard connectors – 5015, 26482, 38999, 24308, 83723,
26500, 83513, Mighty Mouse, ARINC, etc. Moves filtering away from sensitive board electronics when a signal
“barrier” is needed in a system. Can shunt an unwanted electrical surge fast {1X10^-9}
Filters are can be a “planned” addition to an electronic package or, as frequently occurs, added after a problem has been discovered
What Glenair CANNOT Do:
$2 PCB filter solution$1,000,000
board debug problem
FIX THE EMI PROBLEM HERE
When it Comes to Filters…
$300 filter solution
With no re-design necessary at board level
What Glenair CAN Do: Fix the Problem Here
When it Comes to Filters…
Electrical Criteria in Filter Device Specification
Operating temperature Range Working voltage Current rating Surge voltage Dielectric withstanding
voltage Insulation resistance Frequency Range of All
Effected Equipment
Selection of filter device types is affected by the electrical criteria of the equipment:
Multilayer Planar Capacitor Array
Most widely applied type of EMI filter
Design utilizes rugged ceramic capacitor arrays and ferrite inductors in a single block
Available with different capacitance values on individual pins
Connector shell protects the array from thermal, mechanical and environmental damage
Reduced size, weight and superior performance compared
to discrete discoidal or tubular capacitors
Architecture of the planar array enables mixed capacitance values as well as feed-thrus
Basic Filter Array Module Elements
Planar Array Construction The planar array is a monolithic block of ceramic containing
a combination of capacitors, feed-thrus and ground lines/planes.
Common Filter Element Architectures
The mechanical architecture of the capacitor and its inductive elements allows for optimization for different frequency ranges
of interference
C Filter: Single element filter with low self inductance
Pi Filter: Dual capacitors with a single inductive element positioned between
Insertion Loss Evaluation
Measured in decibels (dB), insertion loss must be minimized in low-current electronic systems.
Entire interconnect system contributes to insertion loss; hence the need for grounding and shielding technologies.
Insertion loss values are predictable for each filter type.
Measure of the degradation experienced by a signal when a device, such as a filter connector is inserted
into the transmission path
(Pi)
(Pi)
EMP/HEMP
High Electro Magnetic Pulse (HEMP) refers to the detonation of a nuclear bomb at a high altitude, which generates a very fast pulse (RF) which can be captured by antennas and long unshielded lines, damaging sensitive electronic circuitry. Sometimes referred to as Nuclear EMP (NEMP).
Lightning can also generate destructive EMP. This is referred to as LEMP.
Other potential sources of EMP include electrostatic discharge (ESD)
“EMP can be produced on a large scale using a single nuclear device” - Congressional Research Report
Glenair’s EMP Solution: Transient Voltage Suppression (TVS) Filter
Connectors
TVS technologies shunt EMP voltage transients directly to ground
TVS diodes and diode modules are integrated into the filter connector package
Diodes can be removed/replaced with relative ease
Decision point: can the capacitor absorb the surge or is a TVS device needed to reduce the surge – or both.
Products meet RTCA DO-160 Requirements (electrical performance benchmarks for withstanding EMP, HEMP, lightning strike
and other induced voltage surges)
Protecting Sensitive Circuits from EMP
Glenair manufactured EMI/EMP Sub-Assemblies
Special Technical Considerations and Connector Packaging Options
Space grade applications Hybrid fiber optic/electrical Soldering procedures vs. clips Lead free designs for RoHS Composite materials and lightning Hermetic sealing Operating temps to -55° to 125°C Machined shells/flange location Clinch nuts/helicoils Fixed contacts vs. crimp contacts Variable length PC tails EMI grounding fingers and gaskets Package size issues, such as occur with the
addition of crimp contacts or TVS diodes. Filtered connectors are usually “system” qualified.
Most filter connectors are “custom.” Some design decisions affect performance and compliance
Non-Filtered interconnect systems can be easily upgraded with the addition of a go-between filter adapter.
Filtered Glenair Sav-Con Adapters are installed between the existing plug and receptacle—enabling filtering without having to change exiting connectors or box layouts
Glenair Sav-Con Filter Adapters can be built for any connector series including MIL-DTL-38999, MIL-DTL-26482, MIL-C-83723, MIL-DTL-24308, MIL-C-83513, and others
Filter Adapters (Connector Savers)
Full Spectrum EMI/EMP Product Line
Contact termination: PCB, solder-cup, crimp, etc.
Connector style: Receptacle, Jam Nut, Box or Wall mount, Hermetic, Plug, Adapter, or Thru Bulkhead.
Compatibility: Intermateable with standard (non-filter) connectors
Connector Series: D38999, M83723, M26482, ARINC, M24308, M83513, etc.
Connector types: circulars, rack and panel, D-Sub and Micro, hybrid electrical/fiber optic, etc.
Glenair’s commitment to complete coverage of the popular filter
technologies and connector styles
Standard Part Number Development
Connector Series or Specification Shell Style Insert Arrangement Contact Gender Class Shell Rotation Position Shell Material and Finish Termination Style Temperature Tolerance Equipment Operating Frequency Range Filter Type Filter Capacitance Insertion Loss IR DWV Labeling and Marking Use the Application Checklist!
New Application Development
Applications for Filter Connectors
Avionics Missile Control Systems Radio Transmitters Fire Control Systems Radar and Jamming Devices Satellite Communications
and Sensors Data Transmitters HEMP Protection Many Others
DO-160 High Reliability, Mission Critical Systems
Full-spectrum EMI capabilities: Screening, grounding, and filtering Unmatched depth of knowledge and technical support in filter technology Fast turnaround on both custom and catalog filter connector solutions Turnkey filter connector cable/harness assemblies Free application engineering and design services Advanced lead-free filter packaging Circuit protection diodes available for all connector types Integrated circuit board real-estate within the filter connector envelope State-of-the-art test and qualification capabilities Popular multi-layer array filters available for every Glenair connector Availability: Service, technical support, designs, stock
New for 2007: Glenair Capacitor Array Capability!
Summary: Why Choose Glenair for EMI/EMP Filter Connectors?