Tantalum chip capacitor reliability in high surge and ripple current applications

Relentless miniaturization of electronic circuitry and the general movement from through-hole to surface-mount manufacturing have generated explosive growth in the use of surface mount tantalum chip capacitors. Many of these applications involve substantial exposure to surge and ripple currents. Such exposure invites questions regarding the impact of surge and ripple current on the long-term reliability of tantalum chip capacitors. To facilitate a better understanding of the impact of surge and ripple current on tantalum chip capacitor reliability, theoretical analyses of generic circuits are supported with discussion of experimental data. Simple circuits that highlight the fundamental theoretical principles behind transient surge and steady-state ripple current applications are analyzed and pertinent reliability issues are discussed. The relationship of device ESR (equivalent series resistance) to surge and ripple current robustness and device temperature rise is established theoretically. Surge and ripple current test and measurement methods are briefly discussed and experimental test data are used to support many of the insights that are drawn from theory.<>