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X2Y Fil t e r & De c o u p l i n g
ca pa c i t o r s
The X2Y® Design - A Capacitive Circuit
X2Y® components share many common features with standard multi-layer ceramic capacitors (MLCC) for easy adoption by end-users.
• Same component sizes (0603, 0805, 1206, etc.)
• Same pick and place equipment
• Same dielectric, electrode and termination materials
• Same industry test standards for component reliability
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A standard multi-layer ceramic capacitor (MLCC) consists of opposing electrode layers A & B. The X2Y design adds another set of electrode layers (G) which
effectively surround each existing electrode of a two-terminal capacitor. The only external difference is two additional side terminations, creating a four-terminal
capacitive circuit, which allows circuit designers a multitude of attachment options.
G1
B
A
G2
X2Y® Circuit 1: Filtering
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When used in circuit 1 configuration the X2Y filter capacitor is connected across two signal lines. Differential mode noise is filtered to ground by the two Y
capacitors, A & B. Common mode noise is cancelled within the device.
Experts agree that balance is the key to a “quiet” circuit. X2Y® is a balanced circuit device with two equal
halves, tightly matched in both phase and magnitude with respect to ground. Several advantages are
gained by two balanced capacitors sharing a single ceramic component body.
Signal 1
Ground
Signal 2
A
B
G1
G2
• Exceptional common mode rejection
• Effect of voltage variation eliminated
• Matched line-to-ground capacitance
• Effects of aging & temperature are equal on both caps
InAmp Input Filter Example
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In this example, a single Johanson X2Y component was used to filter noise at the input of a DC
instrumentation amplifier. This reduced component count by 3-to-1 and costs by over 70% vs.
conventional filter components that included 1% film Y-capacitors.
Parameter
X2Y®
10nF
Discrete
10nF, 2 @ 220 pF
Comments
DC offset shift
< 0.1 µV
91 dB
< 0.1 µV
92 dB
Referred to input
Common mode rejection
Source: Analog Devices, “A Designer’s Guide to Instrumentation Amplifiers (2nd Edition)” by Charles Kitchin and Lew Counts
Common Mode Choke Replacement
In this example, a 5 µH common mode choke is replaced by an 0805, 1000pF
X2Y component acheiving superior EMI filtering by a component a fraction
DC Motor EMI Reduction: A Superior Solution
One X2Y component has successfully replaced 7 discrete filter components
while achieving superior EMI filtering.
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of the size and cost.
No Filter
CMC 5uH
X2Y® 1000pF
Ambient
Common Mode Choke
9.0 x 6.0 x 5.0 mm
X2Y®
2.0 x 1.3 x 1.0 mm
2
www.johansondielectrics.com
JOHANSON [ JOHANSON TECHNOLOGY INC. ]
