T491C226M016AT2478

Product Overview – KEMET T491C226M016AT2478

The KEMET T491C226M016AT2478 is a surface-mount solid tantalum capacitor from the T491 Industrial Grade MnO₂ series, designed for modern automated assembly in high-volume electronic products. It is a molded tantalum device with a nominal capacitance of 22 µF, rated voltage of 16 VDC, and a standard 2312 (6032 metric) chip case (manufacturer size code C).

As a member of the KEMET T491 series, the T491C226M016AT2478 leverages established solid tantalum technology combined with updated materials and production processes. The series is designed to meet or exceed EIA standard 535BAAC and is classified as moisture sensitivity level (MSL) 1 under J-STD-020, allowing unlimited floor life under typical factory conditions.

The KEMET T491C226M016AT2478 targets decoupling and filtering roles in DC/DC converters, portable electronics, telecommunications equipment, and various control units, where a stable 22 µF capacitance, compact form factor, and industrial temperature performance are required.

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Electrical Performance and Ratings of the KEMET T491C226M016AT2478

The KEMET T491C226M016AT2478 provides 22 µF capacitance with a tolerance of ±20% (denoted by the “M” in the part code) and a rated DC voltage of 16 V. This combination suits many low- to mid-voltage rails in digital and analog subsystems.

Key electrical characteristics of the KEMET T491C226M016AT2478 include:

- Capacitance: 22 µF

- Capacitance tolerance: ±20%

- Rated voltage: 16 VDC

- ESR (Equivalent Series Resistance): 1.5 Ω (typical series value for this part number)

- Operating temperature range: -55 °C to +125 °C

- Lifetime at maximum temperature: 2,000 hours at 125 °C

Within the broader T491 series, capacitance values span from 0.1 µF to 1,000 µF, voltage ratings range from 2.5 V to 50 VDC, and tolerance options include ±10% and ±20%. The T491C226M016AT2478 occupies a mid-range point within this spectrum, suitable for 16 V rails where moderate ESR is acceptable and board space is constrained.

Frequency-related behavior of the KEMET T491C226M016AT2478 follows the typical solid tantalum profile reflected in series curves:

- ESR generally decreases with increasing frequency up to a certain band, improving high-frequency decoupling.

- Effective capacitance can vary with frequency, so the final in-circuit performance at switching or clock frequencies is best evaluated using the series’ ESR vs. frequency and capacitance vs. frequency characteristics, which are available through KEMET’s standard documentation and simulation tools.

This profile makes the KEMET T491C226M016AT2478 a suitable choice for smoothing low-frequency ripple in DC/DC converters, bias filtering, and general-purpose decoupling where predictable behavior over temperature and frequency is required.

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Package, Dimensions, and Land Pattern of the KEMET T491C226M016AT2478

The KEMET T491C226M016AT2478 uses a molded 2312 (6032 metric) SMD package with the following main dimensions:

- Length: 0.236" (6.00 mm)

- Width: 0.126" (3.20 mm)

- Maximum seated height: 0.110" (2.80 mm)

- Manufacturer size code: C

This geometry places the KEMET T491C226M016AT2478 in a relatively low-profile category, which supports compact designs and height-constrained assemblies, such as densely packed modules or products with low enclosure clearance.

Land pattern and courtyard recommendations for the KEMET T491C226M016AT2478 are derived from the T491 series land dimension guidance (Table 2 in the series documentation). Three density levels are defined:

- Density Level A: For low-density layouts, including wave solder applications or designs requiring a wider process window.

- Density Level B: For moderate component density, providing robust solder joints for standard reflow processes.

- Density Level C: For high component density applications, where pad dimensions are minimized; this level should be validated through qualification testing per IPC-7351.

Using the appropriate land pattern for the KEMET T491C226M016AT2478 allows reliable solder fillets, controlled tombstoning risk, and predictable self-alignment during reflow. In a typical example, a power supply board using a 6032 tantalum footprint might employ Density Level B to balance assembly robustness with layout compactness.

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Reliability, Lifetime, and Qualification of the KEMET T491C226M016AT2478

The KEMET T491C226M016AT2478 inherits the reliability and industrial focus of the T491 Industrial Grade MnO₂ series. The device is rated for:

- 2,000 hours of operation at 125 °C at rated conditions, indicating endurance in elevated-temperature environments such as power modules and industrial control boards.

The series is designed to meet or exceed EIA standard 535BAAC requirements, covering aspects such as electrical performance, environmental testing, and mechanical robustness. The MSL 1 rating under J-STD-020 means the KEMET T491C226M016AT2478 can be stored in ambient production environments without special dry packing requirements, simplifying logistics and assembly planning.

Higher voltage ratings and tighter ESR or tolerance grades can be substituted by the manufacturer within the same size code, sometimes marked with the higher voltage rating. This policy applies at the series level and indicates that, in some cases, the KEMET T491C226M016AT2478 could be shipped with equal or better electrical limits than nominal, while maintaining the 2312 mechanical envelope.

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Derating, Ripple, and Reverse Voltage Behavior of the KEMET T491C226M016AT2478

The T491 family provides recommended voltage derating guidelines that apply to the KEMET T491C226M016AT2478. In practice, using the 16 V-rated device at a lower working voltage (for example, 10–12 V) can support longer life and more margin against surge and transient conditions.

Ripple and power dissipation

Permissible AC ripple applied to the KEMET T491C226M016AT2478 is governed by two constraints:

1. The positive peak of the AC ripple plus any DC bias must not exceed the 16 V rating.

2. The negative peak plus any DC bias must remain within the allowable reverse voltage limits defined for the series.

Maximum power dissipation per case size is specified in the T491 documentation and must be derated with ambient temperature using a temperature compensation multiplier. Using the maximum power dissipation Pmax and the ESR of 1.5 Ω, the allowable rms ripple parameters for the KEMET T491C226M016AT2478 can be calculated:

- Maximum rms ripple current:

I(max) = √(Pmax / R)

- Maximum rms ripple voltage:

E(max) = Z × √(Pmax / R)

where R is the ESR and Z is the impedance at the relevant frequency. For example, in a DC/DC converter output stage using the KEMET T491C226M016AT2478, designers would evaluate ripple current at the switching frequency and ambient temperature, then verify that the computed I(max) exceeds the expected ripple current with margin.

Reverse voltage behavior

As a solid tantalum device, the KEMET T491C226M016AT2478 is polarized. Key points:

- Incorrect polarity connection can result in permanent damage or destruction.

- The positive terminal is identified by a body stripe and, in some cases, a beveled edge.

- Only a small transient reverse voltage is permissible, per the T491 series reverse voltage table, and only for short durations.

- Continuous operation of the KEMET T491C226M016AT2478 in reverse mode is not supported, even when within transient limits.

In practical terms, a control board designer using the KEMET T491C226M016AT2478 for decoupling should ensure layout and keying prevent reversal, especially where connectors might be misplugged or where field wiring is possible.

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Soldering Process and Assembly Considerations for the KEMET T491C226M016AT2478

The KEMET T491C226M016AT2478 is compatible with standard high-volume soldering processes:

- Convection reflow

- Infrared (IR) reflow

- Vapor phase reflow

- Wave soldering (single or dual wave), with process development attention for taller case sizes (the T491C226M016AT2478’s low height reduces this concern)

KEMET recommends preheating the KEMET T491C226M016AT2478 to mitigate thermal shock and mechanical stress. The suggested reflow profile aligns with IPC/J-STD-020D MSL testing conditions, and the devices can withstand up to three reflow passes at these conditions, enabling double-sided reflow or rework cycles within controlled limits.

Hand soldering of the KEMET T491C226M016AT2478 is possible but should be tightly controlled:

- Heat the PCB pad rather than the molded body.

- Apply solder between pad and termination until reflow occurs, then remove the iron promptly.

- Avoid “wiping” along the component edge or touching the top surface of the molded case with the iron.

A slight darkening of the gold-colored epoxy on the KEMET T491C226M016AT2478 may be observed after typical reflow cycles; this color change does not affect performance or marking legibility.

Manufacturer termination options for the T491 series include:

- 100% matte tin (Sn) terminations (standard, denoted by “T”)

- Gold-plated terminations (“G”) for conductive epoxy mounting

- SnPb and non-magnetic variants (“H”, “N”, “M”) on request

The KEMET T491C226M016AT2478, with its standard tin finish, is optimized for modern lead-free reflow lines with good wetting behavior.

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Storage, Handling, and Marking of the KEMET T491C226M016AT2478

For best solderability and handling characteristics, the KEMET T491C226M016AT2478 should be stored under controlled conditions:

- Maximum storage temperature: 40 °C

- Maximum storage humidity: 60% RH

- Avoid large temperature swings to prevent condensation

- Avoid atmospheres containing chlorine or sulfur-bearing compounds

Packaging materials (reels, tape) can deform at elevated temperatures, and peel force characteristics may change, so prolonged exposure to high temperature should be avoided.

For optimal solderability, stock of the KEMET T491C226M016AT2478 is recommended to be used within three years of receipt under recommended storage conditions.

Marking

The KEMET T491C226M016AT2478 features laser-marked cases. Marking typically includes:

- Capacitance code

- Voltage rating code

- Polarity marking (positive stripe)

This marking supports in-line visual verification and automated optical inspection, helping to prevent assembly errors such as polarity reversal or value mix-ups on multi-value boards.

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Tape & Reel Packaging for Automated Placement of the KEMET T491C226M016AT2478

The KEMET T491C226M016AT2478 is supplied in embossed plastic tape and reel packaging compliant with EIA-481, designed for compatibility with standard tape-fed pick-and-place equipment.

Key packaging aspects for the KEMET T491C226M016AT2478 and its series include:

- Tape widths: 8 mm and 12 mm, depending on case size and configuration

- Reel diameters: 7" and 13" options

- Embossed cavity dimensions (A0, B0, K0) designed to:

- Keep the component below the top tape surface

- Allow vertical removal without mechanical restrictions after cover tape removal

- Limit rotation to 20° maximum for 8 mm and 12 mm tapes

- Limit lateral movement to 0.5 mm maximum for 8 mm and 12 mm tapes

Cover tape performance for the KEMET T491C226M016AT2478 follows series requirements:

- Cover tape break force: 1.0 kg minimum

- Cover tape peel strength: within defined force windows, with peel direction opposite to tape travel and an angle of 165°–180° at 300 ± 10 mm/minute pull speed

Reel labeling employs barcodes per EIA standards 556 and 624 and is placed on the side opposite the sprocket holes. The KEMET T491C226M016AT2478 is therefore compatible with automated incoming inspection and component tracking systems.

A typical SMT line using the KEMET T491C226M016AT2478 would load 7" or 13" reels into feeders, relying on controlled cavity dimensions and limited part movement to ensure accurate vision alignment and high-speed placement.

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Simulation and Design-in Support for the KEMET T491C226M016AT2478

KEMET provides the K-SIM simulation platform (accessible at ksim.kemet.com) to support detailed analysis of specific part numbers in the T491 series, including the KEMET T491C226M016AT2478.

K-SIM allows modeling of the KEMET T491C226M016AT2478 behavior under:

- Varying frequency

- Ambient temperature changes

- DC bias conditions

This enables prediction of parameters such as impedance, ESR, and effective capacitance as a function of operating conditions. For instance, a designer evaluating the KEMET T491C226M016AT2478 for a 16 V rail decoupling network can use K-SIM to check ESR at the converter switching frequency and to verify that ripple current limits based on Pmax and ESR are met.

Using such simulation data alongside the nominal datasheet values helps refine component selection and avoid under- or over-specification of the KEMET T491C226M016AT2478 in complex power architectures.

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Environmental Compliance and Safety Notes for the KEMET T491C226M016AT2478

The KEMET T491C226M016AT2478 is manufactured with environmental and regulatory compliance in mind:

- RoHS status: RoHS 3 compliant (6/6) when ordered with 100% Sn solder, gold-plated, or non-magnetic 100% Sn solder terminations

- REACH status: REACH unaffected

- Halogen-free epoxy

- Epoxy compliant with UL94 V-0 flammability rating

- Molded epoxy compliant with outgassing testing per ASTM E595

Export and customs classifications for the KEMET T491C226M016AT2478 include:

- ECCN: EAR99

- HTSUS: 8532.21.0050

Safety-related notes from the series documentation apply to the KEMET T491C226M016AT2478 as a commercial/industrial component:

- Commercial and automotive grade products are not recommended for high-reliability applications or manned spaceflight by the manufacturer.

- Even with strict quality controls, isolated component failures can occur. Designs using the KEMET T491C226M016AT2478 in applications where malfunction could lead to personal injury or property damage should implement protective circuits or system-level redundancy.

These considerations guide the use of the KEMET T491C226M016AT2478 in industrial, communication, and general-purpose electronics, while encouraging appropriate derating and system safeguards in higher-consequence environments.

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Conclusion – Application Fit of the KEMET T491C226M016AT2478

The KEMET T491C226M016AT2478 brings together a 22 µF capacitance value, 16 V rating, and compact 2312 (6032 metric) molded case within an industrial-grade solid tantalum platform. The device operates from -55 °C to +125 °C with a 2,000-hour life rating at maximum temperature, uses established MnO₂ technology, and complies with EIA 535BAAC and MSL 1 handling standards.

Its ESR characteristics, stable capacitance behavior, and robust packaging make the KEMET T491C226M016AT2478 well suited for decoupling and filtering in DC/DC converters, portable systems, telecommunications products, and control electronics. With multiple termination options in the series, RoHS compliance, halogen-free materials, and comprehensive tape-and-reel support, the KEMET T491C226M016AT2478 can be integrated into modern automated assembly flows with predictable electrical and mechanical performance.

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Frequently Asked Questions (FAQ)

Q1. What are the key electrical ratings of the KEMET T491C226M016AT2478?

A1. The KEMET T491C226M016AT2478 has a capacitance of 22 µF with a ±20% tolerance, a rated voltage of 16 VDC, and a typical ESR of 1.5 Ω. It operates from -55 °C to +125 °C and is specified for 2,000 hours at 125 °C within the T491 Industrial Grade MnO₂ series framework.

Q2. In which applications is the KEMET T491C226M016AT2478 typically used?

A2. The KEMET T491C226M016AT2478 is used for decoupling and filtering in DC/DC converters, portable electronics, telecommunications equipment, and various control units. Its 16 V rating and 22 µF value make it suitable for filtering intermediate and low-voltage rails while providing stable performance across temperature.

Q3. What package size does the KEMET T491C226M016AT2478 use, and how large is it?

A3. The KEMET T491C226M016AT2478 is packaged in a 2312 (6032 metric) molded SMD case with size code C. Its dimensions are approximately 6.00 mm in length, 3.20 mm in width, and a maximum seated height of 2.80 mm. This low-profile shape supports compact layouts and height-constrained designs.

Q4. What land pattern should be used for the KEMET T491C226M016AT2478?

A4. Land pattern recommendations for the KEMET T491C226M016AT2478 follow the series’ land dimension guidance (Table 2 in the T491 documentation), with Density Levels A, B, and C for low-, medium-, and high-density designs. Density Level B is often chosen for robust reflow soldering, while Density Level C is used in high-density layouts after qualification per IPC-7351.

Q5. How should ripple current be calculated for the KEMET T491C226M016AT2478?

A5. For the KEMET T491C226M016AT2478, permissible ripple current is derived from maximum power dissipation Pmax (case-dependent) and ESR (1.5 Ω). The rms ripple current limit is:

I(max) = √(Pmax / R)

and rms ripple voltage is E(max) = Z × √(Pmax / R), where Z is the impedance at the intended frequency. The positive peak of the AC ripple plus any DC bias must not exceed 16 V, and the negative peak plus any bias must remain within reverse voltage limits.

Q6. Can the KEMET T491C226M016AT2478 be exposed to reverse voltage?

A6. The KEMET T491C226M016AT2478 is a polarized solid tantalum capacitor. Only a small amount of transient reverse voltage for short periods is allowed as specified in the T491 reverse voltage table. Continuous operation in reverse mode is not supported, even when within transient limits. Polarity must be observed, with the positive terminal identified by the body stripe and sometimes a beveled edge.

Q7. What soldering processes are compatible with the KEMET T491C226M016AT2478?

A7. The KEMET T491C226M016AT2478 is compatible with convection reflow, IR reflow, vapor phase reflow, and wave soldering (single or dual). Preheating is recommended to reduce thermal stress. The device can endure up to three reflow passes at profiles aligned with IPC/J-STD-020D. Hand soldering is possible with controlled technique that avoids direct heating of the molded body.

Q8. Is the KEMET T491C226M016AT2478 suitable for double-sided reflow assembly?

A8. Yes. The KEMET T491C226M016AT2478, with its MSL 1 classification and ability to withstand up to three reflow cycles at specified profiles, can be used in double-sided reflow assemblies, provided that the total number of reflow exposures and thermal profile remain within recommended limits.

Q9. What termination finishes are available for the T491 series, and which apply to the KEMET T491C226M016AT2478?

A9. The T491 series offers several termination finishes, including 100% matte tin (Sn, code “T”), gold-plated (“G”), standard SnPb (“H”), non-magnetic 100% tin (“N”), and non-magnetic SnPb (“M”). The KEMET T491C226M016AT2478 is typically supplied with 100% matte tin terminations, which are compatible with lead-free solder systems and provide good wetting. Other finishes can be specified within the series where required.

Q10. How should the KEMET T491C226M016AT2478 be stored to maintain solderability?

A10. The KEMET T491C226M016AT2478 should be stored at temperatures not exceeding 40 °C and relative humidity not exceeding 60%. Atmospheres should be free of chlorine and sulfur-bearing compounds, and temperature fluctuations should be minimized to avoid condensation. Under these conditions, it is recommended to use stock within three years of receipt for optimal solderability.

Q11. What tape & reel options are available for the KEMET T491C226M016AT2478, and are they compatible with standard pick-and-place machines?

A11. The KEMET T491C226M016AT2478 is delivered in embossed plastic carrier tape on 7" or 13" reels, in 8 mm or 12 mm tape widths, in accordance with EIA-481. Carrier cavities control component rotation (max 20°) and lateral movement (max 0.5 mm), and cover tape peel strength and break force follow EIA guidelines. These features ensure compatibility with standard tape-fed automatic pick-and-place equipment.

Q12. Does the KEMET T491C226M016AT2478 comply with RoHS and REACH requirements?

A12. Yes. The KEMET T491C226M016AT2478 is RoHS 3 compliant (6/6) when ordered with suitable solder finishes such as 100% Sn, gold-plated, or non-magnetic 100% Sn. It is classified as REACH unaffected and uses halogen-free epoxy, with encapsulation materials that comply with UL94 V-0 and ASTM E595 outgassing requirements.

Q13. What is the moisture sensitivity level (MSL) of the KEMET T491C226M016AT2478?

A13. The KEMET T491C226M016AT2478 is rated MSL 1 under J-STD-020. This classification indicates unlimited floor life at ≤30 °C and 85% RH, simplifying handling while still requiring adherence to recommended soldering profiles.

Q14. Can the electrical behavior of the KEMET T491C226M016AT2478 be simulated before design-in?

A14. Yes. The KEMET T491C226M016AT2478 can be modeled using the KEMET K-SIM tool at ksim.kemet.com. K-SIM provides frequency-, temperature-, and DC bias-dependent data such as impedance, ESR, and capacitance, allowing accurate prediction of the component’s in-circuit behavior in decoupling and filtering roles.

Q15. Is the KEMET T491C226M016AT2478 recommended for high-reliability or manned spaceflight applications?

A15. The manufacturer’s documentation indicates that commercial and automotive grade products, including the T491 series and thus the KEMET T491C226M016AT2478, are not recommended for high-reliability or manned spaceflight applications. Designs requiring very high reliability should consider additional safeguards such as protective circuitry or redundancy and should evaluate specialized product lines intended for such environments.