How Do You Choose The Right Type Of NTC Thermistor To Limit Inrush Current For Capacitive Applications? (.PDF Download)

Q: How do you choose the right type of NTC Thermistor to limit inrush current for capacitive applications?

A: Inrush current refers to the maximum, instantaneous input current drawn when power is applied to an electronic system’s power supply. A dc system has an input capacitor and an ac input system has and input rectifier and capacitor that can exhibit high inrush current when the associated equipment turns on. If steps are not taken to minimize this inrush current, it can damage power devices and reduce equipment life. A safe and cost effective way to reduce inrush current is to use an inrush current limiter (surge limiter), which is a special type of negative temperature coefficient (NTC) thermistor.