Power thermistor, surge current suppression

In order to avoid the surge current generated in the boot of the moment in an electronic circuit, connected to a power type NTC thermistor in series in the circuit, can effectively inhibit the surge current during startup, and after complete inhibition of surge current, the electric resistance of power type NTC thermistor will fall to very small degree, not impact on the working current is normal, so the use of power type NTC thermistor in the power supply circuit, is to suppress the surge boot time, to ensure the most simple and effective measures for electronic equipment from damage.

PART NO.	DAE5-D9MUSB			NTC THERMISTOR 2.5 Ω				REV NO.	0/A (Aug.30th,2006 )
1. APPEARANCE
1-1. Dimensions (mm)							1-2. Marking ■    NTC       2.5D-9 □No marking
							1-3.Coating  □ No coating      ■      Coating
							Material       □PF resin       ■Silicon       □Epoxy       □Others			Color  □Green  □Red  □Tan  ■Black  □Blue
							1-4. Leads ■Tin – plated copper wire □Tin-plated steel wire □Straight     □ Axis-formed ■In-Forming  □ No Lead
DMax: 10.5mm		TMax: 6.0mm			F: 5.0±1.0mm
d: 0.8±0.06mm		Lmin:15mm
2. MECHANICAL CHARACTERISTICS
Item			Specification			Test Conditions & Methods
2-1. Solder-ability			The terminals shall be uniformly tinned, and its area≥95%			Dipping theNTC terminals to a depth of 15mm in a soldering bath of 245±5℃ and to the place of 6mm far from NTC body for 3±0.5s (See IEC68-2-20 /GB2423.28 Ta )
2-2. Resistance To Soldering Heat			No visible mechanical damage. ΔR/RN ≤20% (ΔR =∣RN-RN'∣)			Dipping the NTC terminals to a depth of 15mm in a soldering bath of 260±5℃ and to the place for 6mm below from NTC body for 3±0.5s.After recovering4-5h under 25±2℃. The rated zero power resistance value RN' shall be measured. (See IEC68-2-20 /GB2423.28 Tb)

PART NO.	DAE5-D9MUSB		NTC THERMISTOR 2.5 Ω			REV NO.	0/A (Aug. 30th, 2006 )
2-3. Strength of lead terminal		No break out ΔR/RN ≤20% (ΔR =∣RN-RN'∣)		Fasten the body and apply a force gradually to each lead until 10N and then keep for 10sec, Hold body and apply a force to each lead until　 90°slowly at 5N in the direction of lead axis and then keep for 10sec, and do this in the opposite direction repeat for other terminal. After recovering 4~5h under 25±2℃, the rated zero power resistance value RN' shall be measured.  (See IEC68-2-21/GB2423.29 Ua / Ub)
3.ELECTRICAL CHARACTERISTICS
3-1.Test Conditions & Method
Items			Spec.		Test Conditions & Methods
3-1-1.Rated Zero-Power Resistance RN (W)			2.5±20%		Ambient temp. Range:25℃±2℃(TA). Testing voltage: 1.5VDC After placing for 1~2 hours under TA, the resistance value shall be measured.
3-1-2.Thermal Dissipation Constant (mW/°C)			11		The thermal dissipation constant(d) could be calculated by the ratio of a change in power dissipation(DP) of the thermistor to a change in temperature(DT) of the thermistor at a specified ambient temperature
3-1-3.Thermal Time Constant t (s)			35		The time(t) shall be measured within which the temperature change of NTC thermistor is reached at 63.2% of the ambient temperature change under zero power condition
3-1-4.Material Constant B (°K)			2600 B=T1T2/(T2-T1)×Ln (R1/R2)		R1 , R2 is zero-power resistance at T1 , T2 T1 = 298.15°K(25°C)  T2 = 323.15°K(50°C)