TDK has announced the B3272*A/G/T series of DC-link film capacitors, qualified for continuous operation at case temperatures up to 135° C. The parts require no derating up to 105° C. TDK lists xEV traction inverters, on-board chargers and automotive DC-DC converters as main applications, along with industrial drives and high-end power supplies.
The capacitors use TDK’s EPN dielectric, a blend of polypropylene and cyclic olefin copolymer that the company says has already been proven in its ModCap UHP power capacitors. According to TDK, the dielectric gives DC-link designs in automotive and industrial power electronics greater thermal headroom.
In an inverter or charger, the DC-link capacitor absorbs the ripple current drawn by the switching stage, and that current heats the film. Polypropylene film capacitors are normally derated as temperature climbs. TDK says higher power density, confined spaces and higher ambient temperatures put thermal and electrical stress on passive components in these applications.
The series covers rated DC voltages of 800 to 1,200 V and rated capacitance of 1.0 to 60 µF, in two-pin and four-pin versions with lead spacings of 27.5 mm, 37.5 mm and 52.5 mm. Maximum RMS current, specified at 85° C and 10 kHz, runs from 3.5 A to 24 A depending on type. TDK puts useful life at 100,000 hours at rated voltage and 85° C. TDK also lists self-healing properties and overvoltage capability among the series’ features.
TDK says the four-pin G types support low-inductance busbar interfaces and help reduce parasitic loop area in fast-switching inverter stages. The low-profile B32726T, it says, is intended for height-constrained layouts in compact automotive and industrial assemblies.
The flame-retardant plastic case and epoxy resin sealing comply with UL 94 V-0, and the series is AEC-Q200E qualified and RoHS-compatible, according to the company.
TDK provides SPICE model libraries and its web-based Capacitor Life And Rating Application (CLARA) tool for the series.
Source: TDK
