- What are the key design considerations when integrating the KEMET T355E225K050AT into a through-hole PCB layout with tight lead spacing constraints?
- The KEMET T355E225K050AT features a radial package with 0.125" (3.18 mm) lead spacing and a 0.217" (5.50 mm) diameter body, requiring board holes positioned precisely at this pitch. The maximum seated height of 0.402" (10.20 mm) should be factored into enclosure clearance and component height stacking during layout. The conformal coated UltraDip II construction provides mechanical robustness, but designers typically verify solder joint fillet formation and thermal expansion match with the board substrate to maintain long-term connection integrity.
- How does the 3.5 Ohm ESR of the KEMET T355E225K050AT at 100 kHz affect its performance in power supply decoupling or ripple filtering applications?
- With an ESR of 3.5 Ohm measured at 100 kHz, the KEMET T355E225K050AT generates noticeable I²R losses under higher ripple current conditions, which can elevate internal temperature in continuous operation. In low-to-moderate current filtering or bypass roles, this ESR level often provides sufficient damping to control resonances when paired with lower ESR ceramics, while the 2.2 µF capacitance supports energy storage in RC timing or coupling circuits where ultra-low impedance is not the primary requirement.
- Can the KEMET T355E225K050AT be used in applications operating continuously at 125°C, and what voltage considerations apply?
- The KEMET T355E225K050AT is rated for an operating temperature range of -55°C to 125°C. At temperatures approaching 125°C, standard practice involves derating the applied DC voltage to approximately 67% of the 50 V rating (around 33 V) to maintain stability margins, as the dielectric behavior shifts and leakage current increases with sustained thermal stress.
- What factors should engineers evaluate when considering the KEMET T355E225K050AT as a replacement for older radial tantalum capacitors in legacy industrial equipment?
- When migrating to the KEMET T355E225K050AT, verify dimensional compatibility including the 5.50 mm diameter, 10.20 mm max height, and 3.18 mm lead spacing against the existing footprint. The ±10% tolerance and 50 V rating provide a direct match in many general-purpose positions, but the 3.5 Ohm ESR should be compared to the original part, as differences can influence ripple attenuation or damping in filtering networks. The RoHS3 compliant construction and conformal coating offer improved mechanical protection in vibration-prone environments compared to some older uncoated variants.
- Is the KEMET T355E225K050AT suitable for high ripple current circuits in industrial power supplies, and what limitations exist?
- The KEMET T355E225K050AT is generally applied in general-purpose filtering, bypassing, and coupling where ripple currents remain moderate. Its 3.5 Ohm ESR limits the allowable AC ripple voltage to avoid exceeding the device's power dissipation capability, particularly in continuous high-frequency operation. In applications with elevated ripple, engineers often parallel multiple units or combine with lower ESR components to distribute thermal load while retaining the compact radial form factor.
- What configuration or polarity considerations arise when designing circuits with the KEMET T355E225K050AT in timing or coupling applications?
- As a polar solid tantalum device, the KEMET T355E225K050AT requires correct orientation with positive voltage applied to the marked lead (typically the longer lead in radial packages). In RC timing circuits, the low leakage current supports stable time constants over wide temperature swings, while in AC coupling roles, engineers account for the DC bias dependency to ensure the effective capacitance remains within the 2.2 µF ±10% specification under actual operating voltage.
- When migrating from surface-mount tantalum capacitors to the through-hole KEMET T355E225K050AT in repair or redesign scenarios, what practical differences should be anticipated?
- Transitioning to the KEMET T355E225K050AT introduces a radial through-hole mounting style with 3.18 mm lead spacing instead of SMD pads, requiring board redesign or adapter use. The conformal coated case provides additional environmental protection, and the ESR of 3.5 Ohm may differ from low-ESR molded chip tantalums, potentially affecting high-frequency decoupling behavior. The 50 V rating and -55°C to 125°C range typically align well, but thermal management during wave soldering differs from reflow processes used for SMD parts.
- How does the conformal coated construction of the KEMET T355E225K050AT influence its reliability in humid or vibration-heavy industrial environments over extended periods?
- The conformal coating on the KEMET T355E225K050AT enhances resistance to moisture ingress and mechanical stress from vibration or shock, contributing to stable leakage current and capacitance retention in long-term industrial use. Combined with the self-insulating UltraDip II case, this design reduces the risk of external contamination affecting performance, though proper PCB cleaning and conformal coating of the assembled board further support reliability under sustained environmental exposure.
- Are there specific application boundaries where the KEMET T355E225K050AT may not be the optimal choice compared to polymer or ceramic alternatives?
- In circuits demanding very low ESR for minimal output ripple or high transient response, the 3.5 Ohm specification of the KEMET T355E225K050AT can result in higher losses than polymer tantalum or multi-layer ceramic options. For designs prioritizing minimal board area or automated SMD assembly, surface-mount packages offer advantages, while the radial tantalum remains practical for applications needing the specific combination of 2.2 µF at 50 V in a through-hole format with moderate damping characteristics.
- What lead forming or soldering process adjustments are commonly needed when incorporating the KEMET T355E225K050AT into mixed-technology assemblies?
- The KEMET T355E225K050AT leads are typically 0.5 mm diameter and may require forming or trimming to fit automated insertion equipment or specific hole diameters. During wave soldering, preheat profiles should accommodate the conformal coating to prevent thermal shock, while ensuring sufficient but not excessive dwell time to achieve reliable fillets without compromising the 10.20 mm seated height or lead spacing integrity.
