X2Y Technology Presentation – May 2014
© 2014
Page 1
X2Y® Design
MLCC Design
B
G2
B
A
A
G1
G2
A
B
+
=
A
B
G1
Shield Electrodes
A
G1
A
G1
G2
G2
or
B
B
X2Y Technology Presentation – May 2014
© 2014
A
B
Page 2
Low Inductance Design
X2Y®
MLCC
1.
Shorter current path to ground.
2.
Dual current path to ground.
3.
Opposing internal current flow
4. Efficient use of mutual inductance
lowers net ESL when mounted on the PCB.
X2Y Technology Presentation – May 2014
© 2014
Page 3
Two Circuit Solutions
EMI FILTERING (Dual-line)
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•
•
•
CM Choke Replacement
DC-DC HF Filtering
I/O EMI Filtering
RFI Susceptibility Filter
IC POWER BYPASS (Decoupling)
•
•
•
•
Replace 4-7 MLCCs / X2Y
30% Via Reduction
40% PCB Layout Savings
Unparalled Decoupling
Performance
X2Y Technology Presentation – May 2014
© 2014
Page 4
X2Y® Capacitors for EMI Filtering
X2Y® Capacitors, Nearly Ideal Shunts
Two closely matched capacitors in one package.
Considerably less noise-mode conversion then discretes
Very low inductance between terminals.
Extends HF filtering to GHz range
X2Y Technology Presentation – May 2014
© 2014
Page 5
X2Y Circuit Solutions
EMI FILTERING (Dual-line)
•
•
•
•
CM Choke Replacement
DC-DC HF Filtering
I/O EMI Filtering
RFI Susceptibility Filter
IC POWER BYPASS (Decoupling)
•
•
•
•
Replace 4-7 MLCCs / X2Y
30% Via Reduction
40% PCB Layout Savings
Unparalled Decoupling
Performance
X2Y Technology Presentation – May 2014
© 2014
Page 6
Common Mode Filtering Study
•
Common & Differential Mode Noise
•
Filter Solutions Examined
•
Test Comparisons: Series Magnetic vs Shunt X2Y
•
Comparative Applications
•
X2Y Mounting
•
Capacitor Value Selection Methods
X2Y Technology Presentation – May 2014
© 2014
Page 7
Series Magnetic Filters vs Shunt X2Y Filter Study
•
•
•
•
•
•
Agilent E5071C ENA
100 kHz - 8.5 GHz
4-port measurements
Mixed mode derivations
Precision test boards
Short/Open/Load/Through
Calibration to de-embed
fixture effects
X2Y Technology Presentation – May 2014
© 2014
Page 8
Differential Signal Filtering
Mixed mode measurements:
SDD21, shows filter cut off frequency for differential signals
SCD21, mode conversion and radiated emissions
SDC21, mode conversion and EMI susceptibility
SCC21, shows filter cut off frequency for common signals
Key focus: total common mode power past filter
output:
Sum of:
•Source CM power * CM (SCC21) attenuation and
•Source Signal power * mode conversion (SCD21)
X2Y® mode conversion is typically much better than
magnetics
X2Y Technology Presentation – May 2014
© 2014
Page 9
Devices Under Test
DUT
Component Size (mm)
LxWxH
DC Current Rating
X2Y® 1812
4.4 x 3.2 x 2.3
In bypass, no current limit
X2Y® 1206
3.2 x 1.6 x 1.3
In bypass, no current limit
X2Y® 0603
1.6 x 0.8 x 0.7
In bypass, no current limit
(1) 4000 Ohm CMC
5 .0 x 3.6 x 4.3
200 mAmps
(1) 1000 Ohm CMC
5 .0 x 4.7 x 4.5
1500 mAmps
(1) 4.7 mH CMC A
9.0 x 6.0 x 4.8
400 mAmps
(1) 4.7mH CMC B
9.3 x 5.9 x 4.9
400 mAmps
(2) 1uH Chip Inductors
(2) 3.2 x 1.6 x 0.85
1200 mAmps
(2) 120 Ohm Ferrite Beads
(2) 3.2 x 1.6 x 1.1
3000 mAmps
(2) 600 Ohm Ferrite Beads
(2) 3.2 x 1.6 x 1.1
3000 mAmps
X2Y Technology Presentation – May 2014
© 2014
Photo
(not to
scale)
Page 10
Footprint Comparisons
X2Y Technology Presentation – May 2014
© 2014
Page 11
Common Mode Rejection Comparisons
Measured CM Rejection
50Ohm ZSOURCE, 50Ohm ZANTENNA
X2Y Technology Presentation – May 2014
© 2014
Page 12
Common Mode Rejection Comparisons
Measured CM Rejection
50Ohm ZSOURCE, 150Ohm ZANTENNA
X2Y Technology Presentation – May 2014
© 2014
Page 13
Differential to Common Mode Conversion Measurements
Parasitic capacitive
coupling in CM chokes
results in significant mode
conversion at even
modest frequencies.
Typical ≈ -35dB @ 350MHz
(FKNEE IEC 61000-2-4)
Some devices are much
worse
Results in weak ESD
immunity.
X2Y Technology Presentation – May 2014
© 2014
Page 14
Differential to Common Mode Conversion Measurements
Ferrite beads and smaller
value chokes improve
mode conversion, but
exhibit poorer common
mode rejection
X2Y Technology Presentation – May 2014
© 2014
Page 15
Differential to Common Mode Conversion Measurements
Different chokes with the
same datasheet
specifications can result in
dramatically different
mode conversion
characteristics.
LF chokes exhibit
particularly poor mode
conversion at high
frequencies.
X2Y Technology Presentation – May 2014
© 2014
Page 16
Differential to Common Mode Conversion Measurements
X2Y® capacitors convert
a small amount of
differential energy to
common mode due to
finite tolerance
mismatches.
Measured Differential to
Common Mode Conversion
X2Y® 0603 Capacitors
Conversion is -52dB @
350MHz, -40dB
@1GHz
17dB better than typical CM
choke / bead solution
X2Y Technology Presentation – May 2014
© 2014
Page 17
Effect of Mode Conversion on CM Output Power
Upper plot:
Original SCC21 and SCD21 for
common mode choke
Lower Plot:
SCC21 shifted down 20dB to
reflect assumed condition CM
source noise 20dB below signal
Mode conversion dominates
CM output from 300MHz and up
Mode conversion largely
defeats the filter performance
especially at high frequencies
where it is most needed
X2Y Technology Presentation – May 2014
© 2014
Page 18
X2Y® vs CM Choke
Superior mode conversion
of X2Y® capacitors results
in far less HF signal energy
conversion into CM noise
For CM 20dB below signal
at the source, 5.6pF X2Y®
yields substantially less CM
noise at high frequencies
that dominate signal energy
(X2Y® devices must be
selected for acceptable signal
performance.)
X2Y Technology Presentation – May 2014
© 2014
Page 19
Comparative Performance Application
CLASS D AUDIO DRIVER
51µH CMC
3.9KΩ Res
220nF Caps
1206 0.1uF 50V
In this design, a X2Y 1206 0.1uF capacitor
was used to replace a common mode
choke, two resistors and two capacitors to
achieve the filter results shown above.
X2Y Technology Presentation – May 2014
© 2014
Page 20
Test Comparisons
Example, Single Board Computer Power Feed:
68HC11 processor
5uH CM choke tested
PI filter w/ 5uH CM choke tested
0.1uF cap_5uH CM choke_220nF cap
Seven values of X2Y® capacitors tested
47pF, 100pF, 220pF, 330pF, 470pF, 560pF, 1000pF
Radiated Emissions Setup:
GTEM Ets-Lindgren
Computer
Receiver
50 Ohm Coax Cable
X2Y Technology Presentation – May 2014
© 2014
DUT inside
Page 21
Comparative Performance Application
HC11
(50MHz
–1GHz, 1000pF
X2Y)
1MHz
– 500MHz,
1,000pF
X2Y®
X2Y® 1,000pF high frequency radiated
emissions vastly better then CMC or PI
1000pF
X2Y Technology Presentation – May 2014
© 2014
Page 22
X2Y® Capacitors, Best Practices Circuit 1
Performance is typically limited
by external capacitor wiring
inductance:
L3A/L3B, L4A, L4B
Maximize performance by
minimizing L3x, and L4x
inductances.
Follow X2Y® mounting
guidelines.
L1x, and L2x inductance is OK
and even beneficial when
balanced.
Limitation on L2 is to keep
connection close to egress.
X2Y Technology Presentation – May 2014
© 2014
Page 23
X2Y® Capacitors, Best Practices Circuit 1
Locate capacitors close to
bulkhead
Minimize, L3A, L3B
Connect A, B pad connections near
base of pads
Minimize L4A, L4B:
Connect G1/G2 to RF return polygon
on an internal PCB layer as close to the
capacitor surface as possible.
• Chassis for metal enclosures
• Power common plane for plastic
enclosures.
• 12mil vs 4mil upper dielectric costs
about 3dB insertion loss @1GHz
Metal enclosures attach RF return
polygon to chassis w/ low inductance
• Multiple attachments along PCB
edge recommended
X2Y Technology Presentation – May 2014
© 2014
Page 24
X2Y® Capacitors, Best Practices Circuit 1
X2Y Technology Presentation – May 2014
© 2014
Page 25
X2Y® Capacitors, Ethernet Application
X2Y Technology Presentation – May 2014
© 2014
Page 26
Common Mode Summary
• Most EMI problems are Common Mode.
• Reduce common mode by attenuating driving voltage
and/or mismatching antenna impedance.
Properly mounted X2Y® caps do both
• Series elements suffer from mode conversion and/or
poor CM insertion loss at high frequencies.
• X2Y® capacitors maintain good CM insertion loss and
mode conversion figures into the GHz.
X2Y Technology Presentation – May 2014
© 2014
Page 27
X2Y Circuit Solutions
EMI FILTERING (Dual-line)
•
•
•
•
CM Choke Replacement
DC-DC HF Filtering
I/O EMI Filtering
RFI Susceptibility Filter
IC POWER BYPASS (Decoupling)
•
•
•
•
Replace 4-7 MLCCs / X2Y
30% Via Reduction
40% PCB Layout Savings
Unparalled Decoupling
Performance
X2Y Technology Presentation – May 2014
© 2014
Page 28
X2Y® in DC-DC Converters
All commonly deployed DC-DC converter topologies have at
least one switched port.
Parasitic capacitance across filter inductors passes high
frequency switching noise to filtered ports
HF noise propagation through filtered and switched ports is
proportional to filter capacitor mounted ESL at each.
The unique construction of X2Y® capacitors results in
essentially constant mounted ESL in larger body parts such as
1206, as in smaller body parts such as 0603.
Enables massive improvement in filter performance w/o extra
magnetics.
X2Y Technology Presentation – May 2014
© 2014
Page 29
X2Y® in DC-DC Converters
1206 X2Y® vs 1206 MLC (µStrip mounting config.)
|S21| Impedance, 1206 Size MLC vs X2Y®
100Ω
20:1 HF Noise Attenuation
from 60 – 1000 Mhz
Impedance
10Ω
1.0Ω
100mΩ
MLC 1206 0.1µF
HF Impedance
X2Y 1206 1nF
HF Impedance
10mΩ
X2Y 1206 0.1µF
HF Impedance
1mΩ
100kHz
1MHz
10MHz
100MHz
1GHz
10GHz
Frequency
X2Y Technology Presentation – May 2014
© 2014
Page 30
X2Y® in DC-DC Converters
X2Y® Low ESL attenuates HF spikes at both input and output
nodes for all common topologies:
X2Y Technology Presentation – May 2014
© 2014
Page 31
X2Y® in DC-DC Converters
Filter parasitics pass HF noise, often
200MHz or more to output
Solutions:
1) Add series filters
•Increases Cost, Space, DC loss
2) Reduce filter capacitor inductance
MOUNTED ESL (µstrip)
MLC 1206 caps: > 1.0nH
X2Y® 1206 caps: 40-55pH
10X-20X+ better than conventional
1206
Value depends on mounting
configuration
X2Y Technology Presentation – May 2014
© 2014
Page 32
X2Y® in DC-DC Converters
X2Y® low ESL shunts HF
noise:
Noise “Brick Wall”
Reduced EMI from converter
into application PCB
Reduced EMI from application
PCB conducted back through
converter
No extra magnetics
Reduces cost for performance
Saves space
No extra DC drop
X2Y Technology Presentation – May 2014
© 2014
Page 33
Buck DC-DC Converter Input Filter
X2Y® Location
X2Y Technology Presentation – May 2014
© 2014
Page 34
Radiated Emissions from DC-DC Feed
GPS DC-DC Converter
X2Y Technology Presentation – May 2014
© 2014
Page 35
Conducted Emissions from a Commercial Vehicle Lighting
Supply
Multiple output switching power
supply
Original design included many LC,
and Pi form networks to suppress
PCB level noise and conducted
emissions
Replaced these networks at the I/O
w/ X2Y capacitors in Circuit 1
1) One half X2Y to a given I/O
Circuit 2 for decoupling ICs
Big parts count, real-estate, and
cost reduction over and above
massive improvement in
conducted emissions
X2Y Technology Presentation – May 2014
© 2014
Page 36
100+ Semiconductor Manufacturer's Technical
References
X2Y Technology Presentation – May 2014
© 2014
Page 37
Size, Voltage, Capacitance Offering
10
X2Y Technology Presentation – May 2014
© 2014
Page 38
X2Y Eval. & PCB Design Guide
X2Y Technology Presentation – May 2014
© 2014
Page 39
Additional Information: EMI Filtering
•
•
•
•
•
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Common Mode Filter Study (detailed)
GSM RFI Suppression (detailed)
DC Motor Filtering (5 App. Notes)
Low Acoustic Noise (Microphonics) Data
Connector Filtering
Improving Common Mode BW of InAmps
X2Y Technology Presentation – May 2014
© 2014
Page 40
Additional Information: Power Bypass
•
•
•
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Amplifier VCC Noise Comparisons (NEW)
Decoupling FPGAs etc.
Impact of PCB Stack and Via Design on PDN
High Performance Bypass Methods & PDN
Synthesis
• X2Y Advantage on IC Backside
• X2Y Altera Stratix II GX SerDes Bypass Demo
• X2Y Live FPGA Bypass Demo
X2Y Technology Presentation – May 2014
© 2014
Page 41
Technical References
JDI WEBSITE www.johansondielectrics.com
 X2Y Filter Evaluation and PCB Design Guide
 GSM RFI Suppression with X2Y® EMI Filters
 Improve Instrument Amplifier Performance with X2Y Optimized
Input Filter
•
TI Analog Elab Video: GSM Cell Phone Filtering
•
TI Analog Elab Video: Improve Instrumentation Amplifier
Performance Using X2Y Capacitors
•
X2Y DC Motor Filtering Basics
•
Impact of PCB Stack and Via Design on PDN
•
X2Y Altera Stratix II GX SerDes Bypass Demo
•
X2Y Live FPGA Bypass Demo
•
Mounting X2Y for Power Bypass
X2Y Technology Presentation – May 2014
© 2014
Page 42
Thank You !
For Application Information:
Let us show you the advantages of using X2Y® in your products. Johanson Dielectrics, Inc.
can provide application engineering assistance, application specific laboratory test results and
product samples.
For product samples or more technical information please contact
your local representative or:
Steve Cole
X2Y Business Development Mgr.
Tel: (603) 433-6328
Email: scole@johansondielectrics.com
Website: http://www.johansondielectrics.com
X2Y Technology Presentation – May 2014
© 2014
Page 43