TDK Corporation (TSE: 6762) announces the expansion of its NTC temperature sensor portfolio with the M704 (ordering code: B57704M0103A001) and M705 (ordering code: B57705M0103A001) series, engineered for reliable temperature measurement in high-voltage environments. With voltage ratings of up to 4000 V (AC) for the M704 and 2500 V (AC) for the M705, these probe assemblies enable safe and precise monitoring in demanding applications such as UPS and PSU systems in data centers, charging stations, and PV inverters. By combining electrical robustness with ease of assembly, TDK helps designers achieve safe and efficient system operation.

Both sensors feature an R25 of 10 kΩ, a B25/100 value of 3988 K (±1 percent), and a resistance tolerance of ±2 percent. The M704 is specified for a temperature range from -40 °C to +125 °C, while the M705 extends this range up to +180 °C. The M704, with its compact plastic case and 3.5 mm lead spacing, supports automated PCB integration and fast assembly. In contrast, the M705 provides a low thermal time constant of approximately 6.2 s on a metal plate, enabling fast thermal response. It also features a metal-tag ring lug design that ensures excellent thermal coupling and flexible screw-on mounting across various mechanical interfaces.

Together, these portfolio extensions provide robust, application-focused temperature sensing solutions for high-voltage systems where safety, reliability, and installation efficiency are paramount.

TDK Corporation (TSE: 6762) has introduced the compact B3201*A5/B5/C5 series of Y1 safety capacitors designed to suppress EMI in demanding automotive and industrial applications. The metallized polypropylene (MKP) film capacitors are rated for AC voltages of 500 V and DC voltages of up to 1500 V. Featuring a maximum operating temperature of up to +125 °C (with derating), they combine a space-saving footprint with AEC-Q200 Rev. E compliance and high robustness under severe ambient conditions. Typical applications include xEV power electronics, on-board chargers, EV charging infrastructure, industrial drives, power supplies, renewable energy converters, and energy storage systems.

This series offers capacitance values ranging from 0.47 to 33 nF and is available with lead spacings of 15 and 22.5 mm. The smaller B32012 variants measure 5.0 x 10.5 x 18.0 mm, and the B32013 types extend the capacitance range to 33 nF. The compact dimensions help developers implement reliable line-to-ground filtering where PCB space is limited. Parallel wire leads support conventional through-hole mounting. The components are available untaped or in ammo-pack and reel configurations.

The capacitors are rated for continuous operation at 500 V (AC) and 1500 V (DC), respectively, at temperatures of up to +110 °C. At operating temperatures above +110 °C and up to the maximum of +125 °C, the operating voltage must be derated by 1.5% per degree Celsius. Operation within this elevated temperature range is limited to a maximum of 1000 hours.

For applications exposed to heat and humidity, the B3201*A5/B5/C5 series is tested at +85 °C, 85% relative humidity, and 500 V (AC) for 500 hours (THB test). Their self-healing MKP construction supports reliable operation under electrical stress, while the plastic case and epoxy resin sealing meet UL 94 V-0 flammability requirements. The series is approved according to IEC/EN/UL 60384-14, CSA E60384-14, and GB/T 6346.14.

TDK Corporation (TSE: 6762) has expanded its surface-mount multilayer varistor (MLV) product family with the standard X series (CT0402*X, CT0603*X, CT0805*X, CT1206*X, CT1210*X, CT1810*X, and CT2220*X) for industrial applications. These new SMD MLVs not only protect electronics against overvoltages, maintaining high reliability and performance in a compact size, but also help customers reduce their CO₂ footprint by up to 30 percent. Based on a tailored, innovative ceramic composition, these components can be sintered at lower temperatures than standard MLVs, reducing energy usage. Additionally, the raw material itself has a smaller CO₂ footprint.

The X series targets power supplies, factory automation, industrial IoT, and sensor interfaces where miniaturization and electrical robustness are required, including harsh environments. This follows the release and ramp-up of the X1 series for automotive applications based on the same technology platform.

Spanning case sizes from EIA0402 to EIA2220, the X series offers RMS voltage ratings from 3.5 to 40 V and varistor voltages from 8 to 350 V. They provide clamping voltages from 24 to 450 V and withstand electrostatic discharge (ESD) up to 15 kV air discharge according to IEC 61000-4-2. For surge protection, peak current handling ranges from 1 A in the smallest footprint up to 800 A. Customer-specific adjustments are possible.

These varistors respond to voltage transients within 0.5 ns and offer capacitance values as low as 6 pF, preserving signal integrity in high-speed data lines. The components operate reliably in a temperature range of -55 to +125 °C. With packaging options that support high-volume automated assembly, the X series integrates seamlessly into modern SMT processes.

By combining compact dimensions, fast response times, and robust electrical ratings, the X series enhances the resilience of electronic designs, contributing to longer service life and improved system reliability across a diverse set of industrial applications.

Overvoltages and the resulting high surge currents can damage or even destroy electrical and electronic devices. Reliable overvoltage protection is therefore essential. Using a new ceramic material, TDK has now developed a series of multilayer varistors with high surge capabilities, combining compact dimensions with outstanding performance.

Overvoltages affecting electrical devices can arise from various sources, carry different energy levels, and enter systems through multiple paths.

ESD pulses, for example, which are measured according to IEC 61000-4-2, primarily impact the I/O ports of communication devices. These are tested using a voltage of either 8 kV for contact discharge or 15 kV for air discharge. The associated pulse shapes are characterized by an extremely steep edge with rise times in the nanosecond range. However, the energy level of these pulses is relatively low at just a few millijoules. For protection against ESD events, TDK offers a wide range of multilayer varistors (MLVs) in SMD packages across various voltage ratings. The smallest design has a footprint of just 0.4 mm x 0.2 mm with an extremely low height of only 0.23 mm. These varistors are therefore commonly used in compact mobile applications, such as smartphones, tablets, and wearables.

Another form of overvoltage is primarily injected into power supply lines. It may be caused by nearby lightning strikes or by load shedding. These events can cause surge currents of several kiloamperes that last microseconds. In the worst-case scenario, the energy of these pulses can carry several thousand joules of energy, which is several times greater than the energy levels encountered in ESD events. The ability of components to withstand these high-energy pulses is measured according to IEC 61000-4-5, using an 8/20 μs pulse shape for the short-circuit current and a 1.2/50 μs pulse shape for the open-circuit voltage (see Figures 1 and 2).

Pulse shapes according to IEC 61000-4-5

Figure 1:

Measurement of the short circuit current (8/20 μs)

Figure 2:

Measurement of the open-circuit voltage 1.2/50 μs

To ensure effective protection against such events, protection devices must be designed to handle the expected leakage currents and the corresponding energy levels. This is why conventional varistors tend to be relatively large.

New ceramic material enables more compact designs

To improve the performance and compactness of multilayer varistors, TDK has developed a new ceramic material for its new high-surge series of multilayer varistors. Thanks to a higher doping of the ZnO varistors with a special metal oxide, the new ceramic material boasts improved properties and a finer granular structure. This creates significantly more grain boundaries per unit of volume. Consequently, the current density can be increased by more than threefold within the same active volume of the component. At the same time, the relative permittivity increases severalfold, enabling a considerably higher electrical field strength (EV) – also within the same volume (Figure 3).

Figure 3:

Comparison of the conventional and new ceramic material TDK’s new multilayer varistors have a higher field strength thanks to their finer granular structure, which is achieved through a special metal oxide doping of the ZnO ceramic material. This results in two benefits: First, a higher number of internal electrodes can be integrated into the same component volume, thereby improving the high-surge performance. Second, the same performance can be achieved in a smaller component, permitting further miniaturization of the varistors.

Thanks to their improved electrical properties, varistors can now be designed with a higher voltage class by increasing the number of internal electrodes. This significantly raises the surge current capability of the component and allows for shrinking the component size for a given performance level. For example, standard varistors with a surge current capability of 1200 A (8/20 μs) are manufactured in an EIA 2220 case size. With the new ceramic, TDK has achieved the same performance in a 1210 form factor. This corresponds to a volume reduction of more than three times. The new varistors are therefore generally used in Internet of Things (IoT) and Industry 4.0 applications, where miniaturization plays a crucial role.

Lower clamping voltage and higher performance

Thanks to the higher permissible field strength of the new TDK ceramic material and the increased number of internal electrodes, the clamping voltage of the components has also been reduced. The clamping voltage is the value at which the varistor becomes conductive. At a given current level, an increase in clamping voltage leads to higher electrical power (P = V∙I), and ultimately, greater dissipation (E = P∙t) within the varistor. Conversely, smaller clamping voltages allow higher currents to achieve the same energy absorption capability.

For example, the TDK type CT2220K50E2G multilayer varistor from the existing surge protection series has a specified clamping voltage of 135 V at 10 A. In contrast, the new TDK CT2220S50E3G high-surge low-clamp type with the improved material achieves a surge current capability of 400 A at the same clamping voltage (Figure 4). Consequently, the new type provides a significantly higher protection level.

Figure 4:

Higher surge current capability at the same clamping voltage. The new TDK high-surge/low-clamp varistor allows for a surge current of 400 A at a clamping voltage of 135 V.

Fewer components, better protection

To achieve the highest possible surge current capability with SMD multilayer varistors, multiple components are often connected in parallel. However, since varistors have voltage tolerances of up to ±20 percent, it is necessary to use precisely matched components for such applications. This represents a considerable cost factor. Another drawback is that, even with tight tolerances, the electrical characteristics of the individual components vary slightly. Consequently, during an overvoltage event, the current is distributed unevenly among the components, which can cause the most heavily loaded varistor to fail.

Thanks to the new TDK ceramic material, high surge current capability can now be achieved in a single varistor. This enhances reliability, reduces component count, and saves both PCB space and assembly costs.

Key data

• Ultra-compact micro POL module FS3303 delivers 3 A in a 2.5 × 2.5 mm footprint with only 1.2 mm height, enabling high-density power for optical modules and AI edge systems
• High efficiency up to 95% with operation up to +90 °C (and +125 °C with derating), supporting low-voltage rails from 0.4 V to 3.3 V for ASICs, SoCs, DSPs, and AI chipsets
• Integrates controller, driver, MOSFETs, and inductor in TDK’s advanced 3D chip-embedded package, minimizing external components and maximizing board space savings

TDK Corporation (TSE: 6762) today announced the FS3303, the first member of a major expansion of its micro POL family of ultra‑compact, non‑isolated DC‑DC power modules for optical modules in AI edge systems and other space‑constrained designs. Despite its small footprint of just 2.5 x 2.5 mm and a height of only 1.2 mm, the FS3303 can deliver 3 A at ambient temperatures of up to +90 °C (up to +125 °C with derating) and boasts a peak efficiency of around 95%. The FS3303-0400-AL is in full production and is sampling at major distributors.

The FS3303 and the upcoming high‑performance point‑of‑load (POL) converter lineup spans 3 A to 80 A output across 0.3 V to 3.3 V rails. They enable next‑generation optical networking and AI accelerator platforms to push performance without sacrificing board space. An example is compact optical modules, which are scaling from 10 Gbit/s to 1.6 Tbit/s. The new portfolio delivers height profiles between 1.2 mm and 1.7 mm.

Engineered for low‑voltage rails, the FS3303 supports input voltages from 2.7 V to 6 V and output voltages from 0.4 V to 3.3 V. This makes it a versatile solution for ASICs, SoCs, DSPs, and emerging AI chipsets requiring tight regulation and high transient performance.

The FS3303 leverages TDK’s proprietary 3D chip‑embedded packaging technology, integrating the controller, driver, MOSFETs, and power inductor. This architecture minimizes external components and delivers a complete DC‑DC solution with exceptional area and height savings—ideal for next‑generation optical transceivers and edge AI modules.

TDK Corporation (TSE: 6762) presents the B82722V6*B040 series of new compact high-voltage, current-compensated ring-core double chokes. Designed primarily for rated DC voltages of up to 1250 V (630 V AC), these compact common-mode chokes (23 x 15.5 x 24 mm) effectively suppress EMI in next-generation applications. These include power converters, industrial motor drives, and switch-mode power supplies that often deploy SiC and GaN power semiconductors and feature elevated DC bus voltages, where insulation coordination and PCB space are critical.

The series covers nominal inductance values ranging from 3.3 mH to 22 mH, with rated currents between 0.85 A and 3.0 A at a rated ambient temperature of +70 °C. Multilayer solid insulation construction and testing with voltages of 3,750 V (line-to-line) ensure robust electrical isolation. Thanks to the special automated winding technique, these chokes feature high resonance frequency characteristics and a typical stray inductance of around 0.6%, helping to suppress symmetrical interference.

The epoxy coating of the ferrite core and the plastic header comply with UL 94 V-0. The design fulfills the latest IEC 60938-2 and IEC/UL 60939-3 safety requirements for EMI chokes and filters. Suitable for wave soldering and offered in a compact vertical design, the B82722V6*B040 series enables engineers to realize 1250 V DC high-voltage architectures without increasing the PCB footprint.

TDK Corporation (TSE:6762) has introduced the G series of surge protection components, comprising the G14 (ordering code: B72214G) and the G20 (B72220G). Integrating a metal oxide varistor (MOV) and a gas discharge tube (GDT) into a single hybrid design and connecting them in series leverages the strengths of both elements. This configuration reduces leakage current to virtually zero, extends the lifetime of the whole component, and provides superior surge protection compared to using either element separately in parallel. These new components are commonly used in power supplies, chargers, appliances, surge protection devices, and communication systems that demand both efficiency and reliability.

Innovation through series hybrid design:

• Zero standby leakage current: With the GDT isolating the MOV during normal operation, leakage currents are virtually eliminated, maximizing efficiency.

• Extended MOV lifetime: The MOV is only engaging when the GDT has fired, drastically reducing stress and aging.

• Reliable surge handling: When fired, the GDT quickly becomes low resistive and acts as the "first line of defense." Meanwhile, the MOV clamps residual voltages, absorbs remaining energy, and eliminates follow-current to prevent the GDT from reigniting.

• Compact integration: A single hybrid device simplifies design and reduces board space compared to discrete solutions.

The G series is available in two leaded versions: G14 and G20, which refer to MOV disk diameters of 14 mm and 20 mm, respectively. G14 models support AC operating voltages from 50 V to 680 V, while G20 versions extend this range to 750 V. The maximum surge current capability for a single pulse (8/20 µs) is 6,000 A (G14) and 10,000 A (G20), absorbing up to 200 J (G14) or 490 J (G20) of energy. Their operating temperature range is specified as -40 °C to +105 °C.