PTC Thermistor Glossary and Definition

PTC Thermistor Zero Power Resistance

DC resistance value of the thermistor measured under 25C by adopting sufficiently low power consumption.

PTC Thermistor Maximum Operating Voltage (Vmax)

The maximum rated voltage the PTC thermistor can continuously endure at 25C.

PTC Thermistor Maximum Inrush Current

The maximum current (effective value) through the PTC thermistor under max. rated voltage. Exceeding this current may result in damage to the PTC components.

PTC Thermistor Switch Temperature

The temperature at which the resistance value of the PTC thermistor increases to twice the zero-power resistance, also called PTC Thermistor Curie temperature, or PTC Thermistor Reference temperature，or PTC Thermistor transition temperature .

PTC Thermistor Non-trip Current

Also called PTC Thermistor Rated Current or Holding Current,or Non-operating Current， means the current at which PTC thermistor resistance does not exceed the specified value for designated time and temperature conditions.

PTC Thermistor Trip Current

Initial current which causes PTC thermistor resistance to leap, also called PTC Thermistor Operating Current.

PTC Thermistor Temperature Coefficient of Resistance

PTC Temperature coefficient is calculated from the linear range at the steepest portion of resistance(Tb-Tp) as illustrated in Fig.1. メ_T=(LnRp-LnRb) ·100/(Tp-Tb) (%/ìC)

PTC Thermistor Dissipation Factor

The ratio power dissipation change to temperature change of PTC thermistor (in mw/C). =P/(T-Tr) Where P = dissipation power T =thermistor body temperature Tr =room temperature

PTC Thermistor Restore time

Time for restore of PTC thermistor resistance to twice the zero-power resistance after power is switched off.

PTC Thermistor Temperature range under maximum voltage

Operating ambient temperature range that PTC thermistor can continuously operate under maximum voltage.

PTC Thermistor Breakdown voltage

The maximum voltage that PTC thermistor can bear under stipulated time and temperature. PTC thermistor will breakdown exceeding this voltage.

PTC Thermistor Residual current (Ir)

current under heat balance state, after PTC thermistor resistance increases sharply, under maximum operating voltage.



T1,T2 corresponding to R1,R2. Higher 10C, 25C than curie temperature separately.

PTC Thermistor Temperature at minimum resistance

Temperature corresponding to minimum resistance.

PTC Thermistor Upper category temperature

Maximum ambient temperature that PTC thermistor can operate continuously.

PTC Thermistor Low Category Temperature

Minimum ambient temperature that that PTC thermistor can operate continuously.

Insulation Thermistor

thermistor that satisfy stipulated insulation resistance and voltage test requirement.

Non-insulation Thermistor

thermistor that do not require insulation voltage and insulation resistance test.

PTC Thermistor Ininital Current (I_in)

the current that appears instantaneously in circuit switch starting to closing.

PTC Thermistor Peak Current (I_inp-p)

Peak-peak value of initial current.

date: 2007-7-8