The CL-40 is a 2-pin NTC thermistor designed as an inrush current limiter. Its small size provides advantages in product design over larger passive components and solid-state devices for current suppression. The disc thermistor features uninsulated lead wires. It addresses the issue of current surges in switch-mode power supplies, which are caused by large filter capacitors used to smooth rectified ripple currents. The primary function is to limit maximum surge current and protect components in series with the input to DC/DC converters from damage. The thermistor's maximum steady-state current rating is determined by the expected lifespan of the final product. It is suitable for PCB mounting.