MF52 3950 NTC Thermistor – Black Epoxy Coated (1% Accuracy) – Select Your Resistance (1K/1.5K/2K/2.2K/2.7K/3K/3.3K/4.7K/5K/6.8K/10K/15K/20K/30K/40K/47K/50K/100K)

Description

The MF52 series is a precision bead-type NTC thermistor designed for accurate temperature measurement and compensation. It features a B25/50 value of 3950K and is available in a wide range of nominal resistance values at 25°C, from 1KΩ to 100KΩ. The ±1% resistance tolerance and ±1% B-value tolerance (on precision variants) make it suitable for applications where consistent, repeatable temperature readings are required, such as 3D printer hotends, HVAC systems, and battery pack monitoring .

The thermistor element is encapsulated in black epoxy coating, which provides mechanical protection and electrical insulation. The bead is small (approximately 1.7mm pitch for the MF52A series) with tinned copper leads, making it easy to solder into through-hole PCB designs or extend with wiring for remote sensing . The operating temperature range is typically -40°C to +125°C (some variants up to -55°C), with a maximum power dissipation of 50mW and a thermal dissipation coefficient of ≥2mW/°C .

The resistance decreases as temperature rises—a characteristic of all NTC thermistors. To read temperature with a microcontroller, the thermistor is placed in a voltage divider with a fixed resistor (typically equal to the nominal R25 value, e.g., 10KΩ), and the ADC value is converted to resistance, then to temperature using the Beta equation or a lookup table .

Critical limitations: NTC thermistors are non-linear, especially at temperature extremes. The Beta equation is an approximation that is accurate near 25°C but can drift at high or low temperatures. For the best accuracy, use the Steinhart-Hart equation or a manufacturer-provided R-T table . The 1% tolerance applies to the 25°C resistance and B-value; it does not guarantee 1% temperature accuracy across the full range. Self-heating can also cause errors if the measurement current is too high—keep test power below 0.1mW for best results .

Features

• ±1% Resistance Tolerance: Precision R25 value for consistent temperature readings across units .

• B25/50 = 3950K ±1%: Standard Beta value for predictable temperature-resistance curve .

• Wide Resistance Selection (1K–100KΩ): Choose the nominal value that best matches your voltage divider and ADC range.

• Black Epoxy Coating: Protects the bead and provides electrical insulation.

• Small Bead Size: Compact footprint suitable for tight spaces and PCB mounting.

• Fast Thermal Response: Thermal time constant ≤7–12 seconds depending on variant .

• Wide Operating Temperature (-40°C to +125°C): Suitable for most consumer and industrial applications .

• Low Cost and Widely Available: Common thermistor type with abundant library support.

Technical Specifications