Abstract:
Surge current testing is considered one of the most important techniques for evaluating reliability and/or to screen out defective units for tantalum capacitors for low-impedance applications. Analysis of this test, as it is described in the MIL-PRF-55365 document, shows that is does not address several issues that are important to assure adequate and reproducible testing. This work investigates the effect of inductance of the test circuit on voltage and current transients and analyzes requirements for the elements of the circuit, in particular, resistance of the circuit, inductance of wires and resistors, type of switching devices, and characteristics of energy storage bank capacitors. Simple equations to estimate inductance of the circuit to prevent voltage overshooting and minimum duration of charging/discharging cycles to avoid decreasing of the effective voltage and overheating of the parts during surge current testing are suggested.
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