The Knowles Syfer 1111J2000510JQT is a 51 pF multilayer ceramic capacitor designed for precision RF and high-frequency applications where low loss and stable electrical performance across temperature extremes are required. Built with C0G (Class I NP0) dielectric, this component delivers a temperature coefficient effectively at 0 ppm/°C, ensuring capacitance remains stable from -55°C to 125°C without the drift characteristic of Class II dielectrics. The ±5% tolerance (J designation) provides sufficient accuracy for timing circuits, oscillators, and filter networks where moderate precision is acceptable.
Rated at 200 volts, this capacitor supports higher-voltage analog and mixed-signal designs, including power supply filtering in instrumentation, sensor interface circuits, and communication modules. The C0G dielectric exhibits negligible capacitance change with applied voltage, making it suitable for integrators, sample-and-hold stages, and low-distortion signal paths. High Q and low ESR characteristics enable use in resonant tank circuits, impedance matching networks, and RF coupling applications up into the UHF range, where parasitic losses directly impact system efficiency.
The 1111 (2828 metric) package measures 0.110" × 0.110" with a maximum thickness of 0.070" (1.78 mm), offering a compact surface-mount footprint that balances capacitance density with thermal dissipation. This size is particularly suited to densely populated mixed-signal boards, modular power stages, and embedded systems where board real estate is constrained but performance cannot be compromised. The component is qualified to MSL 1, permitting unlimited floor life after opening, which simplifies inventory management and reduces moisture-related assembly risks in volume production.
As a general-purpose ceramic capacitor with active production status and RoHS 3 compliance, the 1111J2000510JQT integrates into both new designs and legacy platform refreshes. Its REACH-unaffected status and EAR99 classification support straightforward procurement and global supply chain operations. Engineers specifying low-loss capacitors for RF front-ends, precision analog conditioning, or stable timing references will find this part delivers predictable performance without the aging, hysteresis, or piezoelectric effects that complicate designs relying on higher-permittivity dielectrics.
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Finding a Practical Knowles Syfer 1111J2000510JQT Replacement Without Creating RF or Layout Risk
Replacing the Knowles Syfer 1111J2000510JQT is not only a matter of matching “51 pF, 200 V, C0G/NP0.” In RF, timing, filtering, impedance-matching, and low-loss capacitor positions, the package geometry, Q factor, dielectric stability, voltage margin, tolerance, solder footprint, and parasitic behavior can affect circuit response.
Common replacement or alternative part numbers to evaluate include:
- Knowles Syfer 1111J2000510FQT
- Knowles Syfer 1111J2000510GQT
- Knowles Syfer 1111J5000510JQT
- Knowles Syfer 1111J2000470JQT
- Knowles Syfer 1111J2000560JQT
- ATC 100B510JT200XT
For a true drop-in replacement, the closest options are parts with the same capacitance, voltage rating, dielectric, and 1111 package. For tuned RF networks, nearby capacitance values such as 47 pF or 56 pF may also be considered when the original 51 pF part is unavailable, provided the circuit is revalidated.
What Defines the Knowles Syfer 1111J2000510JQT 51 pF 200 V C0G/NP0 Capacitor
The Knowles Syfer 1111J2000510JQT is a surface-mount multilayer ceramic capacitor specified as 51 pF with ±5% tolerance, 200 V rated voltage, and C0G/NP0 dielectric in an 1111 package, also known as 2828 metric. Its body size is approximately 2.79 mm x 2.79 mm, with a maximum thickness of 1.78 mm.
| Key specification | Engineering relevance for replacement selection |
|---|---|
| Capacitance: 51 pF | Determines resonant frequency, filter response, coupling level, and impedance-matching behavior. A 47 pF or 56 pF substitute may shift circuit tuning. |
| Tolerance: ±5% | Suitable where some capacitance spread is acceptable. Tighter-tolerance replacements can improve repeatability but may not always be cost-optimized. |
| Rated voltage: 200 V | Replacement should meet or exceed circuit DC bias, RF voltage swing, surge, and derating requirements. |
| Dielectric: C0G/NP0 | Provides low temperature drift, low loss, and stable capacitance versus voltage compared with high-K dielectrics. |
| Package: 1111 / 2828 metric | Affects solder land compatibility, parasitic inductance, RF current handling, and heat spreading. |
| Operating temperature: -55°C to +125°C | Supports industrial and high-reliability environments where capacitance stability is needed across temperature. |
| Features: High Q, low loss | Relevant in RF matching networks, resonant circuits, low-loss filters, oscillators, and precision timing paths. |
| RoHS / REACH / MSL 1 | Helps maintain compliance and simplifies storage and assembly handling. |
The main replacement constraint is that 51 pF is a small capacitance value where parasitic inductance, pad geometry, and dielectric losses may represent a meaningful part of total circuit behavior. A replacement that is electrically equivalent on paper can still alter insertion loss, Q, or resonance if the package construction or termination system differs.
Candidate Equivalent and Alternative Parts for Knowles Syfer 1111J2000510JQT
Part numbers should be checked against the latest manufacturer datasheets and ordering codes before release to production, especially for termination finish, packaging format, tolerance code, and voltage rating.
| Manufacturer | Part Number | Key Specifications | Product Features | Typical Applications | Why It Can Replace the Original Part | Main Differences or Limitations | Recommended Usage |
|---|---|---|---|---|---|---|---|
| Knowles Syfer | 1111J2000510FQT | 51 pF, ±1%, 200 V, C0G/NP0, 1111 package | High Q, low loss, same capacitance and voltage class | RF matching, precision filters, oscillators, stable coupling networks | Same nominal capacitance, same voltage rating, same dielectric family, same package format | Tighter tolerance may affect price and availability; circuit behavior is usually closer, not farther | Best same-family upgrade when tighter capacitance control is preferred |
| Knowles Syfer | 1111J2000510GQT | 51 pF, ±2%, 200 V, C0G/NP0, 1111 package | Stable dielectric, low-loss RF behavior, same package style | RF tuning, impedance matching, low-drift signal paths | Maintains capacitance, voltage, dielectric, and mechanical outline while improving tolerance versus ±5% | Availability and cost may differ from the ±5% original | Suitable drop-in candidate where ±2% tolerance improves production consistency |
| Knowles Syfer | 1111J5000510JQT | 51 pF, ±5%, 500 V, C0G/NP0, 1111 package | Higher voltage margin, stable dielectric, low loss | Higher-voltage RF nodes, pulsed circuits, derated industrial designs | Same capacitance and tolerance with higher voltage rating; package remains 1111 | Higher-voltage construction may have different thickness or parasitic behavior; confirm height and RF model | Use when additional voltage derating is desired and the layout has enough mechanical clearance |
| Knowles Syfer | 1111J2000470JQT | 47 pF, ±5%, 200 V, C0G/NP0, 1111 package | Same dielectric and voltage class with slightly lower capacitance | RF matching adjustment, resonant network trimming, coupling reduction | Mechanically compatible and electrically close for circuits tolerant of lower capacitance | Not a direct equivalent; shifts resonance and impedance | Use only after circuit-level validation or when 47 pF is an approved tuning option |
| Knowles Syfer | 1111J2000560JQT | 56 pF, ±5%, 200 V, C0G/NP0, 1111 package | Same voltage, dielectric, and package with slightly higher capacitance | RF matching adjustment, filter tuning, increased coupling capacitance | Similar construction and footprint; useful when the circuit can accept a higher capacitance value | Not a direct capacitance match; may lower resonant frequency or change filter corner frequency | Use for tuned replacement when measured performance supports the capacitance increase |
| ATC | 100B510JT200XT | 51 pF, ±5%, 200 V class, high-Q RF capacitor, 1111-style RF package | High-Q RF construction, low ESR, low loss | RF power networks, impedance matching, low-loss filters, high-frequency resonant circuits | Same nominal 51 pF value and comparable voltage class; commonly considered for RF-grade capacitor replacement | Cross-manufacturer package height, termination, ESR, Q, and land pattern details must be verified | Consider when a cross-source high-Q RF capacitor is required and qualification testing is available |
The closest electrical replacements are Knowles Syfer 1111J2000510FQT and Knowles Syfer 1111J2000510GQT because they preserve the 51 pF capacitance, 200 V rating, C0G/NP0 dielectric, and 1111 footprint while tightening tolerance. Knowles Syfer 1111J5000510JQT is useful when the design benefits from higher voltage margin. The 47 pF and 56 pF options are not direct equivalents, but they are practical alternatives for tuned networks where the original 51 pF value is part of an adjustable RF response.
Engineering Trade-Offs When Comparing Knowles Syfer 1111J2000510JQT Replacement Options
| Replacement Part | Electrical Compatibility | Mechanical Compatibility | Performance Differences | Reliability and Derating | Package / Supply Considerations | Advantages | Limitations | Suitable Replacement Scenario |
|---|---|---|---|---|---|---|---|---|
| Knowles Syfer 1111J2000510FQT | Strong match: same 51 pF, 200 V, C0G/NP0 with ±1% tolerance | Strong match if termination and packaging suffix match the original | Lower capacitance spread can improve RF repeatability and filter consistency | Same voltage class; apply the same derating approach as the original | Same-family sourcing simplifies qualification | Closest precision upgrade | May cost more or have longer lead time than ±5% part | Preferred for precision RF, oscillator, and matching networks requiring tighter control |
| Knowles Syfer 1111J2000510GQT | Strong match: same nominal value and voltage with ±2% tolerance | Strong match within the same 1111 package family | More controlled capacitance than original with minimal design impact | Similar temperature stability and voltage derating behavior | Same manufacturer and package family reduce approval effort | Balanced option between tolerance, availability, and design fit | Still not the exact original tolerance code | Good general-purpose equivalent when ±2% is acceptable or preferred |
| Knowles Syfer 1111J5000510JQT | Strong capacitance match; higher 500 V rating provides more voltage headroom | Usually compatible, but maximum thickness and solder profile should be checked | Higher-voltage construction may slightly alter parasitics or self-resonance | Improved voltage margin when operated in a 200 V-class position | Availability may differ from 200 V versions | Better derating margin for stressed nodes | Possible size-height or RF model differences | Suitable for higher-voltage RF, pulse, or conservative derating designs |
| Knowles Syfer 1111J2000470JQT | Partial match: same dielectric and voltage, but capacitance is about 8% lower | Strong mechanical match within the same 1111 family | Can raise resonant frequency or reduce coupling compared with 51 pF | Similar dielectric stability and voltage class | Useful if 51 pF stock is constrained and circuit tuning allows change | Maintains package and dielectric behavior | Not a drop-in capacitance equivalent | Use for validated tuning changes, not blind substitution |
| Knowles Syfer 1111J2000560JQT | Partial match: same dielectric and voltage, but capacitance is about 10% higher | Strong mechanical match within the same 1111 family | Can lower resonant frequency or increase coupling versus 51 pF | Similar C0G/NP0 stability and voltage class | Same-family alternative may simplify sourcing | Useful for measured tuning correction | Not suitable where 51 pF tolerance limits must be maintained | Use when lab data supports a higher capacitance value |
| ATC 100B510JT200XT | Good nominal match if datasheet confirms 51 pF, ±5%, 200 V class behavior | Must verify land pattern, height, termination, and assembly compatibility | RF loss, ESR, Q, and self-resonant behavior may differ from Knowles Syfer construction | Strong candidate for RF use, but qualification data should confirm stress margins | Cross-manufacturer sourcing may improve availability but adds approval work | Useful second-source option for high-Q RF applications | Requires validation beyond capacitance and voltage matching | Best for RF designs with available test time for S-parameter or circuit-level verification |
For a lowest-risk replacement path, begin with Knowles Syfer 1111J2000510GQT or Knowles Syfer 1111J2000510FQT. If the original application has higher voltage stress, Knowles Syfer 1111J5000510JQT may provide additional derating margin. If the capacitor is part of an RF tuning network, Knowles Syfer 1111J2000470JQT and Knowles Syfer 1111J2000560JQT can be evaluated as tuning alternatives rather than direct equivalents. ATC 100B510JT200XT is a practical cross-source candidate where RF performance qualification can be performed.
For availability checks, quotations, and sourcing of Knowles Syfer 1111J2000510JQT replacement parts, request pricing through IC-Components.com or email Info@IC-Components.com.
