The MF72 series 5D-9 directly heated power negative temperature coefficient thermistor is specifically designed for inrush current management in high-power electronic systems. Initially, the device exhibits a high resistance of 5Ω, effectively suppressing peak capacitor charging currents. Through self-heating, the resistance rapidly decreases to a residual resistance of 0.21Ω, ensuring efficient steady-state operation under high-current conditions. Its 2700K material constant enables precise control of resistance characteristics over a wide temperature range.
The device has a rated zero-power resistance of 5Ω ±20%, calibrated at 1.5VDC at 25°C. A 35-second thermal time constant and 11mW/°C dissipation factor combine to produce a heat capacity of 385mJ/°C, providing excellent surge protection. Its maximum steady-state current of 3A supports large loads of 220μF in 240V systems or 820μF in 120V systems.
The device operates in a wide -40°C to 175°C temperature range and is certified for extreme thermal cycling at 200°C and 1000 cycles of 3A electrical stress aging. It is suitable for industrial-grade power converters, high-power ballasts, and high-intensity lighting systems.
The enhanced 11mm diameter wafer design with a 5.5mm thickness features a phenolic resin encapsulation and 0.55/0.75mm dual-gauge CP leads. It is available in inward, outward, side, and straight lead mounting options.