Top 10 Knowles Syfer Parts Every Hardware Engineer Should Know

Knowles Syfer has been making multilayer ceramic capacitors (MLCCs) and EMI suppression parts for decades — aerospace, defense, medical, and industrial designs all use them. The reliability reputation is earned; these parts hold up where generic capacitors crack or drift. Knowing the common Syfer part families shortens the design-to-procurement cycle when you're sourcing critical passives.

Here are ten Knowles Syfer parts and families worth keeping in your reference library.

High-Voltage MLCC Workhorses for Power Electronics

1. 2220Y2K00154KXR — High-Voltage X7R MLCC

This 0.15 uF, 2000V rated MLCC in a 2220 package is our go-to for DC-link snubbers and high-voltage filtering in power supplies. The Y2-rated terminal finish meets safety standards for line-to-ground applications. X7R dielectric keeps capacitance stable over a wide temperature range — a real plus on industrial boards.

2. 1812Y1K00224KXR — Mid-Voltage Bulk Capacitance

At 0.22 uF and 1000V in a 1812 package, this part does input-stage filtering in telecom and server PSUs. We pick it for the low ESR and predictable aging. When board space is tight but voltage requirements stay high, it's usually the first MLCC we reach for.

3. 1206Y5000104KXR — General-Purpose 100 nF MLCC

Rated at 500V in a 1206 footprint, this 0.1 uF capacitor is the decoupling workhorse on industrial control boards. It's a direct replacement for many generic high-voltage capacitors when reliability is paramount. You can search for similar capacitors on PartsCube Global to compare alternatives.

4. SMPS StackiCap Range

StackiCap stacks multiple MLCC layers into a single SMD package, delivering capacitance values up to several microfarads at voltages exceeding 1kV. The SMPS StackiCap series (e.g., 2220Y4K00105KXR, 1uF/2000V) is a staple in high-density power modules where through-hole film capacitors simply won't fit. We've used it to replace film caps in dense designs before.

5. 1808Y5000472KXR — 4.7 nF, 500V for EMI Filtering

This 4.7 nF capacitor is a frequent pick for EMI input filters in motor drives and switching converters. The combination of a small 1808 footprint and 500V withstand makes it ideal for Y-capacitor placements in AC-DC stages. It keeps reappearing on BOM after BOM.

6. FlexiCap Range (Flexible Termination)

Knowles Syfer's FlexiCap range uses a flexible polymer termination that absorbs board-bending stress. Parts like 1210Y2K00104KXR (0.1 uF, 2000V) are designed for automotive and avionics PCBs that see thermal cycling and mechanical vibration. We've seen enough cracked large-case MLCCs in the field to know this failure mode is real — FlexiCap reduces the risk.

7. 2220Y5000334KXR — 0.33 uF, 500V Bulk Storage

This part goes into bulk storage and hold-up capacitor banks for intermediate bus converters. In a standard 2220 case it offers an excellent capacitance-to-voltage ratio, and the X7R dielectric means minimal DC bias derating compared to higher-k dielectrics.

8. 1812Y2K00682KXR — 6.8 nF, 2000V Snubber

SiC and GaN-based converters are hard on snubber capacitors — you need ultra-low ESR and high AC voltage capability. This 6.8 nF, 2000V part from the 1812 series is what we usually spec for half-bridge snubber networks in wide-bandgap power stages.

9. 1206Y2K00562KXR — 5.6 nF, 2000V Precision Value

Non-standard capacitance values for timing or resonant circuits are where a catalog like this earns its keep. This 5.6 nF, 2000V rated part in a 1206 package is a common find in resonant LLC converter designs.

10. 2220Y5000224KXR — 0.22 uF, 500V Industrial Grade

Last one on the list, and a solid pick for DC bus filtering in motor controllers and solar inverters. High ripple current capability and low leakage make it suitable for continuous-operation environments.

Why Knowles Syfer Matters for Your BOM

Designing with known, stocked part numbers from manufacturers like Knowles Syfer simplifies both prototyping and volume production. Their broad voltage range and case size options mean fewer line items on your BOM and better supply chain resilience. When evaluating your next power design, cross-reference these parts against PartsCube Global's inventory to check availability and lead times before finalizing your schematic.

Top 10 Knowles Syfer Parts Every Hardware Engineer Should Know