Industry 4.0 is being shaped by the continuing rise in the degree of automation, by the digitalization that includes the Industrial Internet of Things (IIoT) and by high levels of energy efficiency. In this respect, TDK presents a wide range of innovative EPCOS and TDK key components.

High-power loads are a major stress factor when fuses and components are switched on, as they cause very high currents to flow. To avoid this, TDK offers ceramic EPCOS inrush current limiters, based on NTC and PTC thermistors – a strong duo when used in combination.

TDK has an extensive lineup of inrush current limiting NTC thermistors available. This article describes various example applications of these products, used for ICL (inrush current limiting) purposes to easily and effectively suppress inrush current.
When power is first applied to electronic devices such as switching power supplies and inverters, an instantaneous current with an abnormally high peak will flow through them.<br>
This is known as “inrush current” and if not addressed, can lead to problems such as semiconductor element failure or reduced service life of smoothing capacitors. However, our inrush current limiting NTC thermistors can provide protection against this phenomenon to prevent such undesirable effects.

One of the properties of PTC thermistors is that when an excessively large current flows, they generate heat by themselves and become highly resistive. With this property, they are used as overcurrent protection devices. This article describes applications for inrush current limiting, overcurrent protection and telecom application.

PTC thermistors have the property that their resistance rises significantly when a certain temperature is exceeded. This property makes them suitable for use as temperature protection devices that detect defined high temperatures to protect circuits from overheating. TDK offers various types of PTC limit temperature sensors and motor protection sensors that incorporate PTC thermistors and serve as temperature protection devices. This article describes typical applications of such sensors.

Varistors can be used as suppressors to protect devices and circuits from transient abnormal voltages including an ESD (electrostatic discharge) and a lightning surge. For protection from a relatively large surge current (100A to 25kA), leaded disk varistors and SMD disk varistors are suitable. For protection from a larger surge current (approximately 25kA or more), block varistors, and strap varistors are suitable.
This article describes surge protection device applications for LED lighting system, inductive loads such as motors, motor with an electromagnetic brake, SSR (solid-state relay), load dump and field decay, joint boxes and power conditioners of solar power generation systems, important devices using a lightning transformer, and high-energy surge in industrial devices.

SMD or chip varistors are voltage-dependent resistors based on ceramic multilayer technology. They are widely used to protect electronic circuits in consumer devices and telecom, industrial and automotive applications against transient overvoltages, such as electrostatic discharges (ESD) and surge transients.

Chip varistors have both surge absorption capabilities and noise suppressing effects.
See the adaptive application fields of various components for ESD countermeasures as well as the optimal application fields of TDK’s chip varistors / ceramic transient voltage suppressors, CeraDiodes, and multilayer chip protectors.

TDK’s chip varistors in the AVR series, which are made with our own materials, feature high resistance to repeated surges. Products that substitute Zener diodes in compact devices such as solenoid valves and stepping motors, which are rapidly and frequently turned on and off, are also available.

NTC thermistors are heat-sensitive resistor elements of which resistance values rapidly decrease with rise of temperature. With this property, they are used as temperature protection devices for protecting circuits from overheating as well as temperature sensors.
TDK offers various sizes of both TDK brand and EPCOS brand SMD NTC thermistors by capitalizing on our accumulated material technologies and a multilayer processing technology. This article describes temperature protection device applications for temperature detection and temperature compensation.