MCL20 500100-A Thermistor 

The News: Ametherm introduces a new PTC circuit protection thermistor with an industry-high 680 V voltage rating.

Mouser Electronics     Digi Key

Key Benefits:

PTC Thermistor for Inrush Current High 680 V voltage rating

Maximum inrush current of 20 A at maximum peak voltage

Resistance at 25 °C of 50 Ω, with a tolerance of 20 %

Dissipation constant of 55.0 mW/°C

Heat capacity of 5.45 J/°C

Thermal time constant of 62 s

Radial-leaded for easy PCB mounting

19 mm diameter, 9 mm maximum profile, and 7.8 mm lead spacing


Available with straight leads and outside or inside kinked leads

Target Applications:

·   Inrush current limiting and overcurrent protection in applications such as welding equipment and plasma cutters with extremely high voltages from 480 V to 930 V

Key Specifications:

Max. Voltage Rating

680 V

Max. Inrush Current

20 A

Thermal Constant

62 s

Dissipation Constant

55 mW/°C

Heat Capacity

5.45 J/°C

Resistance at 25°C

50 Ω


20 %


19 mm

Operating Temperature Range

-50 °C to +150 °C

The Context: With its industry-high voltage rating, Ametherm’s MCL20 500100-A can withstand hundreds of hits of maximum inrush current without degrading. The device offers a short reset time, and as a PTC thermistor a quick reset will not result in a large inrush current, as its resistance is already at a high state. The result is extremely high reliability and stability in high-voltage applications. With a 19 mm diameter, 9 mm maximum profile, and 7.8 mm lead spacing, the MCL20 500100-A provides designers with a more compact and cost-effective alternative to combining a power resistor, relay, and timer on one circuit to achieve the same functionality.

Availability: Offered direct or through Ametherm’s network of distributors (, samples and production quantities of the MCL20 500100-A are available now, with factory lead times of seven weeks.

More info:

Download this New Product Announcement as a PDF:

Request a Sample: Call 800-808-2434 (toll free in the United States) or 775-884-2434 from outside the U.S. and Canada.


try a free sample