MF71-1D-25MY 1Ω 20A Power NTC Thermistor for Inrush Current Protection in Switching Power Supplies

Price Negotiable

Price: 0.5~1USD/PC

MOQ: 1000PCS

Delivery Time: 10 workdays

Brand: AMPFORT

Product Description

MF71 Series Power NTC Thermistor - 1Ω 20A Inrush Current Protection

Product Overview

The MF71-1D-25MY is a high-performance negative temperature coefficient thermistor specifically designed for inrush current suppression in switching power supplies. With a 1Ω resistance at 25°C and 20A maximum steady-state current rating, this component provides reliable protection against power surge damage.

Key Specifications

Parameter	Value
Zero Power Resistance at 25°C	1Ω ±20%
Maximum Steady-State Current	20A
Capacitance at 240V AC	1200μF
Thermal Dissipation Constant	≥30 mW/°C
Thermal Time Constant	≤130S
Operating Temperature Range	-40°C to +200°C
Rating Power	7.0W

Physical Dimensions

MF71-1D-25MY NTC Thermistor dimensional drawing showing 25mm diameter and terminal specifications

Model	Dmax	P±1	d±0.05	Amin	Tmax
MF71-1D-25MY	30	7.5/10	1.0	7	8

Performance Characteristics

Item	Test Methods	Specifications
Zero Power Resistance at 25°C	Resistance measured at DC current when self-heat generation does not occur	1±20% Ω
Thermal Dissipation Constant	Power required to raise temperature by 1°C in still air	≥30 mW/°C
Maximum Steady-State Current	Maximum DC current at specified temperature without airflow cooling	20A
Thermal Time Constant	Time for temperature to reach (1-1/e) of temperature difference	≤130S
Voltage Withstanding	1000V AC applied between terminals and coating for one minute	No damage, ΔR/R ≤ ±20%
Insulation Resistance	Measured at 1000V DC for one minute	≥500 MΩ

Wave Soldering Process

Preheat temperature: 100-120°C, Time: 86-100 seconds, Heating rate: 1-2°C/second
Molten tin immersion: 255-260°C, Time: 2.5-3.5 seconds
Cooling rate: 1-3°C/second
Total welding time: 3.5 minutes maximum

Storage Conditions