AS Series: Inrush Current Limiting NTC Thermistors

The News:Ametherm introduces new inrush current limiting NTC thermistors designed to withstand high currents from 6 A to 50 A and 250 J to 800 J of input energy

Key Benefits:

  •  Recognized by Underwriters Laboratories (UL) for ensured safety
  • Enhanced performance over traditional inrush current limiters:
  • Lower current density
  • Faster reset times
  • Wider temperature range without derating
  • One-component solution
AS Series Inrush Current Limiter

Key Specifications:

  • Withstand high currents from 6 A to 50 A and 250 J to 800 J of input energy
  • Hot R from 0.0074 Ω to 0.380 Ω · Resistance at 25 ºC from .50 Ω to 50 Ω
  • Maximum capacitance at 680 VAC from 500 µF to 1730 µF
  • Available with diameters of 30 mm and 36 mm

Target Applications:

  • Protection of pre-charge circuits in lithium ion batteries; variable-frequency drives in sports equipment like treadmills, high-speed computers, and processors; switch mode power supplies for plasma cutters and welders; and audio amplifiers, MRIs, and x-ray machines

Key Specifications:

D Max
T Nom
AS32 0R536 Y 0.5 30 300 29 8 995-AS32-0R536-100 570-1103-ND
AS32 0R530 Y 0.5 30 300 29 5 995-AS32-0R530-100 570-1118-ND
AS32 1R030 Y 1.0 30 300 30 8 995-AS32-1R030 570-1104-ND
AS32 1R036 Y 1.0 36 300 30 8 995-AS32-1R036-100 570-1119-ND
AS32 2R025 Y 2.0 25 300 30 8 995-AS32-2R025 570-1105-ND
AS32 5R020 Y 5.0 20 300 32 8 995-AS32-5R020 570-1106-ND
AS32 10015 Y 10.0 15 250 30 9 995-AS32-10015 570-1107-ND
AS32 20010   20.0 10 250 29 9   570-1108-ND  
AS32 50006   50.0 6 250 30 9   570-1109-ND  

The Context:
Designed to withstand high steady-state currents and input energy, AS Series inrush current limiting NTC thermistors reduce costs and greatly simplifying designs by providing simple one-component alternatives to using power resistors with timers and relays. Compared to traditional inrush current limiters, the devices offer lower current density, faster reset times, and a wider temperature range without derating. While traditional inrush current limiters handle approximately 167 A per square inch for the duration of the inrush current, AS Series devices are designed to withstand 400 A per square inch. This lower current density, in combination with a uniform temperature gradient throughout the disc, increases reliability by eliminating hot spots from fatigue.

Availability: Samples of the AS Series are available in three to five days. Production quantities are available with lead times of four weeks.


Download this New Product Announcement as a PDF: AS Series New Product Announcement – July 2013

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