Why Can a GDT Keep Conducting After a Surge?
A gas discharge tube (GDT) can finish diverting the specified surge and still remain conductive. Once the tube has fired...
MLCC Aging and De-Aging: Capacitance After Reflow and Referee Time
An MLCC that measures higher after reflow has not gained permanent capacitance. For a high-permittivity ferroelectric dielectric, a heat history...
How to Read MOV TOV Data: Temporary Withstand Is Not MCOV
If a datasheet states 1.25 per unit for 1 second, the duration and voltage reference are part of the rating....
How Should the Third Lead of a Thermally Protected MOV Be Wired?
The third lead on a thermally protected metal oxide varistor (MOV) often invites the wrong first question. Designers ask whether...
Why Does Ferrite-Bead Impedance Fall Under DC Bias?
A ferrite bead can remain below its catalog current rating and still provide less useful impedance than the filter design...
Does an NTC Inrush Limiter’s Cold Resistance Predict Its Steady-State Voltage Drop?
Does the 5 Ω, 10 Ω, or 20 Ω printed in an NTC inrush-current limiter's datasheet predict the voltage it...
Why Are GDT DC and Impulse Sparkover Voltages Different?
Why can one gas discharge tube (GDT) have a DC sparkover voltage and a substantially higher impulse sparkover voltage? The...
Why Do MOV Leads and PCB Traces Increase Residual Voltage?
Why can the voltage at a protected circuit exceed the metal oxide varistor (MOV) clamping voltage in the datasheet? The...
Can an MOV AC MCOV Be Calculated Directly From Its DC Rating?
No. Dividing a metal oxide varistor's maximum DC operating voltage by √2 does not create an allowable AC rating. The...
How Should MOV Leakage Current Be Read From a Datasheet?
A leakage-current figure in an MOV datasheet is easy to misuse. A few microamperes can look like a fixed property...
