X2Y Circuit 1: Filtering
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.
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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.
- Exceptional common mode rejection
- Effects of aging & temperature are equal on both caps
- Effect of voltage variation eliminated
- Matched line-to-ground capacitance
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InAmp Input Filter Example
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.
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 of the size and cost.
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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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Eliminating Capacitor Anti-Resonance Issue
A common design practice is to parallel decade capacitance values to extend the high frequency performance of the filter network. This causes an unintende and often over-looked effect of anti-resonant peaks in the filter networks combined impedance. X2Y's very low mounted inductance allows designers to use a single, higher value part and completely avoid the anti-resonance problem. The impedance graph on right shows the combined mounted impedance of a 1nF, 10nF & 100nF 0402 MLC in parrallel in RED. The MLC networks anti-resonance peaks are nearly 10 times the desired impedance. A 100nF and 47nF X2Y are plotted in BLUE and GREEN. (The total capacitance of X2Y (Circuit 2) is twice the value, or 200nF and 98nF in this example.) The sigle X2Y is clearly superior to the three paralleled MLCs.
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Decade MLCs versus X2Y Impedance
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Signal Line Filter for USB & RJ45
One X2Y® component can effectively filter high speed signal lines replacing replacing multiple inductive and ferrite components.
Other X2Y® Filter Applications
DC-DC converters, power I/O, connectors (RJ45, D-sub), audio/voice/data, CAN, high-speed differential.
Effectively replaces common mode chokes, inductors, ferrites and feedthru capacitors.
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X2Y Products 