The NTC thermistor is a thermally sensitive resistor whose resistance decreases rapidly as the temperature rises. This property can be utilized in various applications such as temperature sensors and thermal protection devices to protect circuits from overheating.
By mounting the NTC thermistor in close proximity to the heat source, it can accurately sense the temperature of the heat source. However, in some cases, such as when there are constraints on the size of the board or the pattern layout, it may need to be mounted in a location away from the heat source.
In this article, considering such conditions, we used the LEDs on the LED flash circuit board as the heat source and simulated heat generation to check the temperature difference between the LEDs and the NTC thermistors caused by the different mounting positions. We also checked the effect of circuit board thickness.

Universal Serial Bus (USB) is a well-established industry standard that has been in place for more than 20 years, defining the serial communication protocol and the connectors, cables, and chargers for battery-powered rechargeable portable devices. With each updated version of the USB, protocol data rates have continuously increased over the years. Today, we have USB4® protocol, with up to 40 Gbps data rates. Followed by the recently released USB Power Delivery (PD) charging protocol. This development meant a reduction in the time required for charging any peripheral device via USB plug, even though the battery capacities of peripheral devices have been increasing. The latest market developments pushing the technology trends to support requirements have been led by manufacturers’ offerings, followed by attempts to standardize the equipment used. One of the widely used solutions that combines the above requirements is the USB Type-C® connector, which supports up to 100 W power supply option.

Chip varistors and TVS diodes are commonly used as over-voltage protection components.
Their structural design and manufacturing methods are completely different, but they offer similar characteristics with regard to protection from static electricity.
They generally can therefore be used interchangeably in a circuit, but there are cases where chip varistors are considered to be not suitable.
For historical reasons, many of the specification items given in catalogs and data sheets are different, which makes it difficult to compare characteristics based solely on these data, unlike in the case of capacitors and other general components.
The aim of this article is to clarify the difference between varistors and diodes and to introduce data that can be used to compare the two.

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.

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.

Surge arresters are GDT (gas discharge tube) voltage protection devices. TDK offers a strong lineup of products with a variety of surge current capabilities ranging from lightning protection for power lines to lightning protection for signal lines.

TDK’s chip varistors are ESD protection components that can solve various needs that are specific to audio lines. We shall now explain the various advantages providing the optimal solutions for the audio lines of smartphones.