TDK Electronics · TDK Europe

SMD PTC Inrush Current Limiters (ICLs)

 Intro Pic

The world’s first SMD PTC thermistor from TDK uses the PTC effect to automatically limit the inrush current and to protect itself and the electrical circuit behind it in case of a failure. The very compact SMD design allows up to 70 percent space and weight reduction on the PCB and fast processability in automated production lines. Therefore, it is ideally suited for numerous industrial and automotive applications.



Space and weight

  • Space and weight savings on the PCB (ca. 70%)
  • Faster and more cost-effective processability at the customer due to the possibility of reflow soldering
  • High reliability due to encased PTC thermistors with clamp contacts


  • Provides protection in case of a short circuit of DC link capacitors
  • Resettability, i.e. the device returns automatically to the original value when the fault is cleared and the temperature falls to a safe level.


Temperature range

  • High operating temperature range -40 to +125 °C
  • The high thermal constant enables the absorption of high energy. 
  • AECQ-200 qualified


 Traction inverters
 EV Charging Stations
 Variable Speed Drives

Get data sheets and search

PDF Design
Inrush current limiter, SMD

In order to download up to 20 files together as zip, please mark them with the check box. To start the download, please click the Download button at the end of the list.


Frequently Asked Questions

What is the advantage of a PTC thermistor as an inrush current limiter compared to a fixed resistor?

PTC thermistors are self-regulating and protect the circuit behind them as well as themselves from overcurrent by automatically increasing their resistance value with rising temperatures. Furthermore, the PTC element does not need to be replaced after a tripping event because it resets itself when the cause of the failure is cleared and the temperature returns to a safe level.

What properties of a PTC device should be given special consideration when designing an application circuit compared to a normal fixed resistor?

Not only the component or temperature dependency of the PTC resistor must be taken into account, but also the voltage or frequency dependency, because these influence the maximum current value that can be applied to the application circuit. Please refer to 6.1 and 6.2 of PTC general technical information

How should an appropriate PTC product be selected?

An inrush current limiter PTC should be carefully selected according to the specified design target. First, the number of PTC elements required must be determined using the equation described in each data sheet. This includes the circuit design specifications as well as the PTC specifications of interest, such as reference temperature or heat capacitance. For consecutive charging/discharging cycles in a short period of time, a higher number of PTC elements might be required because heat dissipation may be limited within the time to the next cycle.

Product resources

Get in contact

Sales Network & Sites

If you are interested in our products, you will find here an overview of our worldwide sales offices, which you can contact quickly and easily


Product Inquiry

Are you interested in our solutions? Please do not hesitate to contact us! We will be glad to help you.


Tradeshows & Events

Experience TDK live!


Social Media

Follow us on

LinkedIn Twitter