IN Brief:
- The B3272*A/G/T film-capacitor family is rated for continuous operation at case temperatures up to 135°C.
- Devices cover 800V to 1200V and 1µF to 60µF, with two-pin, four-pin, and low-profile package options.
- The series is AEC-Q200E qualified and uses an EPN dielectric combining polypropylene and cyclic olefin copolymer.
TDK has introduced the B3272*A/G/T family of DC-link film capacitors, extending continuous case-temperature operation to 135°C for automotive and industrial power conversion.
The range covers rated voltages from 800V to 1200V and capacitance values from 1µF to 60µF. No voltage derating is required up to a 105°C case temperature, giving converter designers additional thermal margin before the permitted operating voltage begins to reduce towards the 135°C maximum.
The capacitors use TDK’s EPN dielectric, which combines polypropylene with cyclic olefin copolymer. The same material system has previously been used in the company’s larger ModCap UHP power capacitors and is now being applied to PCB-mounted DC-link devices.
DC-link capacitors stabilise the intermediate high-voltage rail in power converters while carrying ripple current generated by switching stages. Their thermal performance affects both electrical behaviour and service life, particularly as inverter and DC-DC converter power density increases.
That thermal pressure is rising as silicon carbide and gallium nitride switches allow power stages to operate at higher switching frequencies and within smaller mechanical envelopes. Semiconductor loss may fall, but passive components are then positioned closer to hot switching devices, magnetics, busbars, and cooling structures.
The new TDK family is available with 27.5mm, 37.5mm, and 52.5mm lead spacing. Standard two-terminal variants address conventional PCB layouts, while four-terminal G versions support low-inductance connection to busbar structures.
Lower connection inductance becomes increasingly useful as switching transitions accelerate. Parasitic inductance in the current loop contributes to voltage overshoot, ringing, electromagnetic noise, and additional semiconductor stress, making the physical connection between the switching stage and DC-link capacitor part of the electrical design.
The B32726T variants reduce package height for assemblies where vertical space is limited. The wider family consequently gives designers several mechanical choices across capacitance, voltage, lead spacing, terminal count, and package profile rather than forcing one enclosure around the complete range.
TDK’s published data lists maximum RMS current values reaching 24A at 85°C and 10kHz for selected four-terminal devices. The largest B32728G parts provide capacitance up to 60µF with 52.5mm lead spacing, while smaller two-terminal versions begin at 1µF.
The capacitors are AEC-Q200E qualified and use flame-retardant plastic housings and epoxy resin sealing compliant with UL 94 V-0. TDK quotes a useful life of 100,000 hours at rated voltage and 85°C, although service life in a converter will depend on the actual voltage, temperature, ripple current, cooling, and operating profile applied to each device.
Traction inverters and onboard chargers are among the target automotive applications, alongside industrial drives, DC-DC converters, and high-end power supplies. These systems commonly combine high DC-link voltage with substantial ripple current and limited cooling volume, placing temperature and current capability among the main constraints on capacitor selection.
A higher temperature rating does not eliminate derating or thermal analysis. Operation above 105°C still reduces the permissible voltage, while hotspot temperature inside the capacitor can differ from the measured case temperature according to ripple-current loss and the thermal resistance of the mounting arrangement.
TDK provides SPICE model libraries and its CLARA capacitor life and rating tool for the new family. These allow device selection to account for operating conditions rather than relying only on the marked capacitance and rated voltage.
Film capacitors remain one of several technologies used on high-voltage DC links. Larger modular capacitors can support greater energy storage and current, while electrolytic or ceramic components address different combinations of density, impedance, cost, and lifetime. The B3272*A/G/T range is aimed at PCB and busbar assemblies where film technology provides an appropriate balance of ripple capability, lifetime, and self-healing behaviour.
The 135°C ceiling expands the design envelope without changing the underlying role of the component. As power converters become smaller and hotter, that additional thermal margin can reduce the extent to which the DC-link capacitor determines enclosure size, airflow, or the distance required between passive components and the switching stage.
