860160578030

FAQFrequently Asked Questions

• Can the Würth Elektronik 860160578030 820µF capacitor be used as a direct replacement for the Nichicon UPJ1E821MHD1TO in a legacy power supply design? The 860160578030 shares the same 820µF capacitance and 35V rating as the UPJ1E821MHD1TO, but replacement requires verification of three critical parameters. First, confirm the ESR specification of your original design—while the 860160578030 specifies 68 mOhms impedance at 100 kHz, the UPJ1E821MHD1TO may have different ESR characteristics that affect ripple current handling and thermal performance. Second, check the physical footprint; although both are radial cans with 5mm lead spacing, the 860160578030's 13mm diameter and 21.5mm height may not fit if your PCB layout was designed for a different can size. Third, verify the ripple current requirement at your operating frequency—the 860160578030 handles 1.818 A at 100 kHz, which may be insufficient if your application demands higher frequency ripple current than the original design specification.
• How does the 7000-hour lifetime rating at 105°C for the Würth Elektronik 860160578030 affect reliability planning in industrial equipment expected to operate for 10 years? The 7000-hour @ 105°C rating on the 860160578030 represents the point at which capacitance degradation and leakage current increase significantly under worst-case continuous operation at maximum temperature. For a 10-year (87,600-hour) design life, this capacitor will experience substantial degradation if operated continuously at 105°C. Using the industry rule that capacitor life doubles for every 10°C reduction in temperature, operating the 860160578030 at 85°C extends effective life to approximately 28,000 hours, still insufficient for 10-year continuous duty. Designs must either employ thermal management to keep the capacitor below 70°C, use redundant capacitors with parallel connection to mitigate individual unit failure, or select a higher-grade product with longer lifetime rating. Periodic replacement intervals of 5-7 years may be necessary if the 860160578030 cannot be thermally controlled.
• What are the design implications when replacing an aluminum electrolytic capacitor rated at 50V with the Würth Elektronik 860160578030 (35V rated)? Derating from 50V to 35V with the 860160578030 introduces risk if your circuit experiences voltage transients or overshoot conditions. Aluminum electrolytic capacitors like the 860160578030 have limited overvoltage tolerance—exceeding the 35V rating by more than 10-15% for sustained periods degrades the oxide layer and increases leakage current exponentially, potentially causing catastrophic failure. If your original 50V design included margin for 10-15% voltage overshoot from switching regulators or line transients, the 860160578030 may not provide adequate safety margin. Additionally, the ±20% tolerance on the 860160578030's capacitance means actual values range from 656µF to 984µF; if your circuit relies on precise capacitance for filtering or timing-critical functions, this tolerance variation could affect performance. Before substituting the 860160578030 for a 50V-rated unit, confirm that your steady-state voltage remains below 32V and that transient overshoot is predictable and controlled.
• Why might the Würth Elektronik 860160578030 be unsuitable for high-frequency switching power supplies despite adequate ripple current rating? While the 860160578030 specifies 1.818 A ripple current at 100 kHz, it may be marginal for modern high-frequency switching converters operating at 200 kHz or higher. The ripple current rating provided typically applies at a single frequency; capacitive impedance (and ESR heating) varies with frequency. At frequencies significantly above 100 kHz, the 68 mOhms ESR becomes less dominant compared to capacitive reactance, and the actual thermal dissipation can exceed design assumptions if the impedance curve is not verified across your full operating bandwidth. Additionally, the 7000-hour thermal rating combined with high-frequency ripple current in a confined PCB environment creates a compounding thermal stress—internal temperature rise from I²R losses in the ESR can push the capacitor significantly above ambient temperature, accelerating degradation. For switching frequencies above 150 kHz, or for applications with continuous high ripple current, a polymer electrolytic or film capacitor may offer better performance despite higher cost.
• Can the Würth Elektronik 860160578030 be used in a -40°C to +85°C industrial environment, and what derating is necessary? The 860160578030 operates across -55°C to +105°C, which covers the -40°C to +85°C industrial range. However, the manufacturer's 7000-hour lifetime specification is referenced to 105°C operation; at 85°C, capacitor life is estimated at roughly double that value (~14,000 hours assuming a 10°C doubling rule), though this is vendor-dependent and should be confirmed from the manufacturer. At the lower end, operation at -40°C presents a different concern: electrolytic capacitor impedance increases significantly at low temperature due to reduced ionic mobility in the electrolyte. The 860160578030's ESR at -40°C could be 2-3 times higher than the 68 mOhm specification (typically measured at 20°C), meaning ripple current handling degrades in cold environments. If your application requires full ripple current performance at -40°C, thermal testing or selection of a low-ESR variant is necessary. For general industrial use at -40°C to +85°C, the 860160578030 is suitable, but ripple current budgets should assume reduced margin below 0°C.
• What is the practical difference between the Würth Elektronik 860160578030 and the Panasonic UPA1V821MHD1TO when selecting a capacitor for a 30V DC power bus with 50% duty-cycle transient load? Both capacitors share 820µF capacitance and 35V rating, making them electrically similar on paper. The key difference lies in ripple current handling and lifetime under transient conditions. The 860160578030 specifies 1.818 A ripple current at 100 kHz; the UPA1V821MHD1TO (Panasonic's equivalent) may have different ESR and ripple current ratings depending on the specific grade. Panasonic's V-series typically offers lower ESR variants optimized for transient response, which benefits 50% duty-cycle loads where capacitors absorb and release energy repeatedly. For a 30V bus with transient load, lower ESR directly translates to better voltage regulation during load steps. The 860160578030's 68 mOhms impedance is moderate; if transient voltage droop exceeds design limits, the Panasonic UPA1V821MHD1TO may perform better if it offers ESR below 50 mOhms. However, the 860160578030 is generally more cost-effective and sufficient for non-critical applications. If voltage stability or thermal margin is critical, request detailed ESR vs. frequency curves from both manufacturers and compare at your actual operating frequency and duty cycle.
• Is the Würth Elektronik 860160578030 acceptable for use in automotive or aerospace applications, and what additional qualification is needed? The 860160578030 is marked as ROHS3 compliant and REACH unaffected, but it is classified as a general-purpose product without automotive (AEC-Q) or aerospace (MIL-SPEC) qualification in its standard form. Automotive applications require AEC-Q200: certification with defined screening, burn-in, and reliability testing; aerospace applications require MIL-SPEC qualification or equivalent. The general-purpose WCAP-ATLL series may not meet these stringent requirements. If your automotive or aerospace program requires the 860160578030, contact Würth Elektronik directly to determine if qualified variants exist or if independent screening and testing can be performed to establish reliability for your specific application. Proceeding with an unqualified capacitor in these safety-critical applications creates regulatory and liability risk. Cost savings from using general-purpose parts are typically outweighed by qualification and re-certification costs if failures occur.
• How should the Würth Elektronik 860160578030 be mounted and secured to withstand mechanical vibration in transportation or industrial equipment? The 860160578030 is a through-hole radial capacitor with 5mm lead spacing and 13mm diameter can. With a seated height of 21.5mm, it is relatively tall and can experience stress from vibration if not mechanically secured. Standard PCB solder joints alone may be insufficient for high-vibration environments (such as vehicles, rail systems, or industrial machinery). Best practices include: (1) using strain relief clamps or adhesive potting compounds around the lead-to-can junction to prevent flexing, (2) positioning the capacitor low on the PCB to minimize vibration amplitude, and (3) avoiding lead bending beyond the first 5mm from the can body during assembly. The radial configuration distributes mechanical stress differently than axial capacitors; ensure that the PCB layout does not create cantilever stress on a single lead. If operating in environments exceeding 2 Gs continuous or 5 Gs peak acceleration, vibration analysis should be performed to confirm lead stress remains within material limits. Inadequate mechanical support can lead to lead fractures and intermittent open circuits, particularly in thermal cycling scenarios where solder fatigue compounds vibration stress.
• What is the minimum clearance and cooling airflow requirement around the Würth Elektronik 860160578030 to maintain thermal stability in a confined enclosure? The 860160578030's 7000-hour lifetime is specified at 105°C internal temperature. The capacitor itself generates heat internally from ESR losses during ripple current; in a confined space, this self-heating can significantly elevate the actual operating temperature above ambient. For a conservative design, maintain at least 50mm clearance around the capacitor can to allow natural convection cooling, or employ directed forced-air cooling if the enclosure temperature exceeds 60°C. If the 860160578030 is mounted vertically (leads pointing down), place it away from other heat-generating components (switching regulators, resistors) to avoid thermal coupling. The ripple current of 1.818 A at 100 kHz produces internal I²R losses of approximately 225 mW at full load; in a sealed enclosure with poor thermal design, this can raise internal capacitor temperature by 30-50°C above ambient. To estimate actual operating temperature: measure or simulate the temperature at the PCB location where the capacitor is mounted, then add the self-heating margin based on your ripple current level. If internal temperature is predicted to exceed 85°C during normal operation, either increase cooling or reduce ripple current burden through circuit redesign.
• Can the Würth Elektronik 860160578030 be used in parallel with film or ceramic capacitors to improve overall performance in a high-frequency filtering stage? Yes, parallel connection of the 860160578030 with film or ceramic capacitors is a common design strategy to combine benefits. The 860160578030 provides large capacitance (820µF) and moderate ESR for bulk energy storage and low-frequency filtering, while film or ceramic capacitors (typically 1-100µF range) provide low ESR and lower inductance for high-frequency ripple attenuation. When connected in parallel, total capacitance is the sum of individual capacitors; however, ESR and equivalent series inductance (ESL) become dominated by the lowest-ESR device. Ensure the parallel connection does not create parallel resonance issues: if the 860160578030 has higher inductance from its radial leads, and a ceramic capacitor has very low inductance, their impedance curves may intersect at a resonant frequency, causing impedance peaking and potential instability. Use a simulation tool (SPICE) or manufacturer-provided impedance curves to verify that combined impedance remains monotonically decreasing across your frequency range of interest. Physical placement is critical: mount the high-frequency capacitors (ceramic or film) as close as possible to the load, and place the 860160578030 remotely with short traces to power entry points. This prevents the inductor of the 860160578030's leads from dominating the high-frequency response.
• What are the cost and lead-time trade-offs when selecting the Würth Elektronik 860160578030 versus alternative 820µF 35V capacitors from other manufacturers? The 860160578030 is a general-purpose WCAP-ATLL series part with moderate pricing and typically good availability due to Würth Elektronik's distribution reach. Comparable alternatives include the Nichicon UPJ1E821MHD1TO, Panasonic UPA1V821MHD1TO, and Rubycon UPM1E821MHD1TO. Lead times and pricing vary based on current market conditions and supply chain status. The 860160578030 often has faster lead times (4-8 weeks) from direct Würth distributors, while specialty variants or less-common manufacturers may have longer lead times (12-16 weeks). Pricing typically ranges within 15-25% across equivalent general-purpose parts; cost difference is usually justified by availability and supply chain stability rather than performance differentiation. If your project has long lead-time constraints, identify 2-3 approved alternatives early and maintain flexibility in your design to accommodate physical or performance variations. Sole-sourcing the 860160578030 in high-volume production risks supply disruptions; qualifying 1-2 drop-in alternatives reduces risk.
• How does the ±20% capacitance tolerance of the Würth Elektronik 860160578030 affect circuit performance in applications with tight filtering or timing specifications? The ±20% tolerance on the 860160578030 means actual capacitance can range from 656µF to 984µF—a 48% spread across the population. For general-purpose filtering in power supplies or audio circuits, this tolerance is acceptable because filtering performance degrades gradually and the application remains functional. However, in circuits with tighter specifications, ±20% tolerance introduces risk. For example, in resonant circuits, PFC (power factor correction) stages, or precision timing circuits, capacitance variation directly shifts resonant frequency, phase relationships, or time constants. A 820µF capacitor specified as ±5% would provide better performance consistency. Additionally, if your design margin assumes 820µF nominal but the worst-case minimum (656µF) falls outside acceptable performance limits, the 860160578030 is unsuitable. When capacitance tolerance matters, either: (1) select a tighter-tolerance variant if available from Würth Elektronik (often at higher cost), (2) design the circuit with sufficient margin to accommodate ±20% variation, or (3) use a tuning element (variable resistor or capacitor) to compensate for tolerance stack-up. Test the circuit with the minimum and maximum capacitance values to confirm performance remains within specification.