Purchased component
Aluminium Electrolytic Capacitor
✓ Expert reviewed All content on this page has been reviewed by a senior motor engineer.
Process flow
Upstream manufacturing of this bought-in item is not covered yet; see the incoming inspection and approval tests.
Incoming inspection & approval tests
- Capacitance, ESR and leakage currentIEC 60384-4
- Endurance (load life)IEC 60384-4, e.g. 2,000–5,000 h at 105 °C
- Ripple current ratingPer data sheet at the application frequency
- Authenticity and traceabilityOriginal packaging, date code and certificate of conformity from the maker or an authorised distributor
Buyer FAQ
- What limits electrolytic capacitor life?
- Temperature and ripple current. Life roughly doubles for every 10 °C below the rated temperature, so the hot-spot temperature on your board decides the real lifetime.
- Which series should I use for a motor driver?
- Low-ESR, high-ripple series rated 105 °C or 125 °C, with life of 5,000–10,000 h at rated temperature. Polymer or hybrid capacitors suit high ripple in compact designs.
- How do I size the bulk capacitor?
- Size by the ripple current from PWM switching (often 0.3–0.5× phase current RMS), not just by capacitance; place it close to the MOSFET bridge to keep loop inductance low.