10D-20 Negative Temperature Coefficient Thermistor

10D-20 Negative Temperature Coefficient Thermistor is a robust, reliable power NTC device specifically engineered to suppress high-current surges in electronic power supplies and circuits. Consequently, this component protects sensitive electronics from the damaging effects of inrush current by providing high initial resistance that decreases as the device heats up. Because the resistance drops rapidly once the current flows, the thermistor ensures minimal power loss during steady-state operation. Furthermore, the large 20 mm disk diameter allows for superior power dissipation and high current handling compared to smaller variants. Therefore, you should integrate the 10D-20 NTC thermistor into your power management designs to enhance system longevity and prevent blown fuses or tripped breakers during start-up.

Key Features:

• High Inrush Current Suppression: Effectively limits peak current during initial power-up to protect downstream capacitors and rectifiers.
• High Power Dissipation: The 20 mm disk size provides a large surface area, which allows the device to manage higher steady-state currents safely.
• Fast Response Time: The high-quality ceramic material reacts quickly to temperature changes, ensuring a smooth transition from high to low resistance.
• Cost-Effective Protection: Offers a simple, space-saving, and inexpensive alternative to active soft-start circuits using relays and resistors.
• Durable Coating: Features a protective phenolic or silicone resin coating that withstands high operating temperatures and environmental stress.

Technical Specifications:

• Zero-Power Resistance (R₂₅): 10 Ω ±20% at 25°C
• Maximum Steady State Current: 6 A
• Approximate Resistance at Max Current: 0.180 Ω
• Thermal Dissipation Constant (δ): ≈ 24 mW/°C
• Thermal Time Constant (τ): ≈ 102 seconds
• Operating Temperature Range: −55°C to +200°C

Mechanical Specifications:

• Component Type: Radial Leaded Power NTC
• Material: Metal Oxide Ceramic Disk
• Coating: Flame Retardant Epoxy/Phenolic Resin
• Lead Type: Straight or Kinked Tinned Copper Wire

Dimensions:

• Disk Diameter (D): ≈ 20 mm (Max 22.5 mm)
• Body Thickness (T): ≈ 5.0 mm to 7.0 mm
• Lead Pitch (P): 10.0 mm ±1.0 mm
• Lead Length: ≈ 25 mm
• Lead Diameter: 1.0 mm

Pinout and Wiring:

• Connection Point A: Connect one lead to the incoming AC or DC live line.
• Connection Point B: Connect the second lead in series with the load or the input of the rectifier bridge.
• Wiring Note: However, users must ensure the thermistor has adequate airflow, as the body becomes very hot during normal operation. Always mount the device with sufficient clearance from heat-sensitive components like electrolytic capacitors.

Datasheet Reference:

• Download MF72 Series (10D-20) Power NTC Datasheet

Commonly Used in:

• Switching Power Supplies (SMPS): Limiting the initial charging current of large input filter capacitors.
• Variable Frequency Drives (VFDs): Protecting power modules from the high energy spikes during initial grid connection.
• Consumer Electronics: Standard in CRT televisions, high-end audio amplifiers, and microwave ovens.

Applications:

• AC/DC Power Converters: Serves as a primary inrush current limiter (ICL) on the input side.
• Motor Starters: Softens the start-up impact on the electrical system for small to medium AC motors.
• Uninterruptible Power Supplies (UPS): Protects internal circuitry when switching between battery and mains power.

Equivalent Models:

• MF72-10D20: The most common alternative part number based on the MF72 series standard.
• NTC-10D-20: A generic manufacturer designation often found in industrial catalogs.
• SCK-1006: A similar power NTC from Thinking Electronic Industrial with 10 Ω resistance and 6 A current rating.

Package Includes:

• 1 x 10D-20 Negative Temperature Coefficient (NTC) Thermistor