TDK Highlighting Solutions for Power Electronics at PCIM Europe

April 15, 2019 by Paul Shepard

TDK will be presenting its comprehensive and innovative portfolio of EPCOS and TDK components for power electronics and e-mobility. The focus is on capacitors for the dc link and EMI suppression. Also highlighted are inductors and protection devices for all kinds of power supplies.

The proven CeraLink® capacitors are now available with FA types in modular flex-assembly technology. This space-saving design connects two, three or ten identical capacitors in parallel over the same terminals in order to increase the capacitance. The new CeraLink FA types are available for rated voltages of 500Vdc, 700Vdc and 900Vdc.

Depending on the voltage and number of capacitors, this results in rated capacitance values of between 0.5µF and 10µF. One particular feature of these capacitors based on PLZT (lead lanthanum zirconate titanate) ceramics is their high permissible operating temperature of 150°C. The FA types have a width of 7.4mm and a height of 9.1mm; while the lengths are 6.3mm, 9.3mm or 30.3mm. Despite their small size, they feature a ripple current capability of up to 47Arms.

One major advantage of the parallel switching is the extremely low ESR values that are significantly below 10mΩ at high frequencies in the range from 0.1MHz to 1MHz. With a minimum of 3nH, the ESL values are also extremely low. Thanks to their low parasitic effects, CeraLink capacitors are suited for converter topologies on the basis of fast-switching semiconductors such as GaN or SiC.

Voltage overshoots when switching are significantly lower than with conventional capacitor technologies. Special requirements in terms of size, current capability and temperature can also be met very easily with CeraLink capacitors.

Stacked MEGACAP Type MLCCs with high capacitance

The new series of vertically stacked MEGACAP Type MLCCs combine high capacitance and low ESR. The new CA series offers rated voltages from 25V to 1000V and covers a capacitance range from 20nF to 150µF. The new MLCCs are available with C0G, X7T, X7S, and X7R temperature characteristics.

Thanks to their high capacitance values, the capacitors are suitable for the resonant circuits of wireless and plug-in charging systems, for example, for industrial vehicles and robots. They can also be used in smoothing and decoupling applications in industrial equipment.


The MEGACAP Type MLCCs feature metal lead frames attached to the electrode ends of the components to protect against board flexure cracks and solder cracks from thermal shocks. The metal material of the terminal has also been optimized to lower the ESR and achieve a higher ripple current capability.

In order to enable a low profile with increased capacitance, TDK has adapted its MEGACAP stack design so that the MLCC elements are stacked side by side.

The vertically stacked design enables stacks with three or even more elements. Hybrid joints between the metal terminals and the MLCC are both soldered and clamped to prevent the individual MLCC elements from falling out of the lead frame at the increasingly higher reflow temperatures.

Series of rugged AC filter capacitors extended

The EPCOS B32754* to B32758* series of ac filter capacitors has been extended. They now cover a range of voltages from 250Vac to 400Vac and offer capacitances of between 1µF and 70µF. The capacitors comply with IEC 61071: 2007 and are extremely robust, even at high humidity. This has been verified in a temperature, humidity, bias (THB) test at 60°C, 95 percent relative humidity and an applied rated voltage for 1344 hours, corresponding to 56 days, in according to IEC 60384 14:2013/AMD1:2016 Grade 3 Test A.

The capacitors are designed for a maximum operating temperature of 105°C, and their epoxy resin-filled case conforms to UL 94 V-0. Depending on capacitance and rated voltage, the lead spacing is 27.5mm, 37.5mm, or 52.5mm.

Thanks to their robustness, the capacitors are suitable for demanding applications in industrial electronics. These include, for example, output filtering for power supplies, frequency converters for drives and renewable energy, or UPS systems.

Compact single-ended series with high current capability


A new series of EPCOS single-ended aluminum electrolytic capacitors feature a particularly compact design, a high CV product and high ripple current capability. The capacitors of the B41897* series are available for rated voltages of between 25Vdc and 75Vdc and cover a capacitance range from 270µF to 12,000µF.

The dimensions of the new components range from 12.5mm x 20mm to 18mm x 40mm (d x l) depending on the voltage and capacitance. Thanks to the use of improved materials, the new capacitors can be exposed to high temperatures and are designed for continuous operation at up to 135°C and for a peak temperature of 150°C.

In comparison with previous series, it has been possible to increase the ripple current capability while at the same time raising the capacitance by as much as 60 percent. This means that the maximum ripple current capability is now higher than 7A at 125°C and 100kHz. Typical applications include automotive ECUs and power supplies.

SMT high-current chokes with a compact design

The EPCOS ERU SMT power inductors has been extended with the ERU16 choke series that comprises ten different types. The inductance values of the new B82559*A016 series extend from 1.0µH to 30µH and their saturation currents range from 9.2Adc to 37Adc. The outstanding feature of these power inductors is their compact design: With a footprint of just 17.3mm x 18.7mm, they have low insertion heights of 7.55mm (1.0µH) to 10.95mm (30µH), depending on the type.

This low-profile design is based on a flat rectangular helical winding technology which results in lower losses. The dc resistances are between 1.05mΩ and 15.35mΩ. With the ERU16 types TDK has expanded its broad spectrum of ERU SMT power inductors, which include the existing ERU13, ERU19, ERU20 and ERU25 series.

The high-current chokes are designed for operating temperatures of between -40°C and +150°C. Its additional third soldering pad results in high mechanical stability on the PCB. They can be used as output and storage chokes in a wide variety of power supply topologies. These include point-of-load (POL) converters, dc-dc converters, high-current switch-mode power supplies, solar converters and xEV applications. The components of the new series are RoHS-compatible and qualified to AEC-Q200.

Miniaturized thin-film metal power inductors suitable for ADAS applications


The new TFM252012ALVA thin-film metal power inductors can be connected directly to a 12V car battery while maintaining small dimensions with a footprint of just 2.5mm × 2.0mm and a height of 1.2mm. Thanks to the magnetic metal core these newly developed inductors offer a rated current of 1.6A and an inductance of 4.7μH.

They are able to withstand severe temperature environments with an operating temperature range of -55°C to +150°C (including increase by self-heating) and are therefore especially suited for automotive power circuits.

To date, no thin-film metal inductors featuring a footprint smaller than 9 mm2 are on the market that can be used coupled to a 12V car battery. The newly developed TFM252012ALVA inductor achieves a rated voltage of 40V with a footprint smaller than 9 mm2, thanks to the material technologies and structural design unique to TDK, and thus can be used in power circuits with an input directly coupled from a 12V car battery.

HVC series with high current capabilities up to 500A

The HVC series of high-voltage contactors has been expanded with the new HVC300 and HVC500 types with current capabilities of 300A and 500A, respectively. The new contactors can switch high voltages of up to 900Vdc, while types for 1200Vdc are available on request.

Their gas-filled switching chamber ensures that arcs are safely and quickly extinguished when the current is switched off. Thanks to the extremely fast switching capability of the HVC high-voltage contactors the duration of arcs is especially short, thus enabling reliable operations over the entire lifetime of the contactor.

The new types have the same compact design as the HVC200 for 200A with the same dimensions of 89mm x 44mm x 93.5mm (l x w x h). Like the HVC200, the new high-voltage contactors are available with coils for operating voltages of 12V or 24V. In addition, the series includes types with an output for switching status detection.

The HVC series is especially suitable for use in battery management systems and dc charging stations in e-mobility applications. Further applications include dc traction systems, photovoltaic, energy storage systems, and uninterruptable power supplies (UPS). These applications require fast and reliable disconnecting from the dc source.

Compact overvoltage protection with an integrated fuse

The EPCOS ThermoFuse™ family of fuse protected varistors has been extended with the new compact NT14 and NT20 series. The new ThermoFuse components feature a footprint that fits into existing circuit board layouts. The NT14 series (disk diameter 14mm) is designed to absorb maximum surge currents with an 8/20-μs pulse of 6kA at rated voltages of between 13Vrms and 680Vrms, while the NT20 series (disk diameter 20mm) has a surge current capability with an 8/20-μs pulse of 10kA at rated voltages of between 130Vrms and 750Vrms.

The NT14 and NT20 series offer a maximum energy absorption of up to 220J and 480J for 2ms, respectively. Both series are available in 2-leaded and 3-leaded types, with the third lead used to monitor whether the fuse has been activated.

ThermoFuse varistors are uniquely designed disk varistors that are connected in series with a thermally coupled fuse and are therefore intrinsically safe. If the varistor overheats, the patented thermal fuse trips and isolates the varistor from the grid with unrivalled dependability. This prevents any potential damage on the PCB or to components located near the varistor and increases the reliability of the equipment to be protected. Thanks to their thermal resistance and flame-retardant design of the epoxy coating, the ThermoFuse NT series meet UL 94 V-0 requirements, and are also listed as Type 4CA in UL 1449, 4th edition.