TDK Corporation introduced the ModCap UHP (B25648A) series of DC-link capacitors designed for high-current applications in power electronics. The ModCap UHP series supports continuous operation at hotspot temperatures up to +105 °C without power derating. Previous ModCap generations required derating starting at +90 °C. The new series achieves this through a high-temperature dielectric combined with a modular design, resulting in a specified lifetime of 200,000 hours at +105 °C and a 20% higher current density compared to earlier versions.
The capacitors have DC voltage ratings from 1350 V to 1800 V and capacitance values ranging from 470 µF to 880 µF. They feature very low ESL of 8 nH and are optimized for SiC semiconductor-based inverters requiring low inductance and high-frequency performance.
The cubic design measures 205 × 90 × 170 mm (L × W × H), which facilitates busbar integration, increases power density in compact converters, and reduces the need for additional snubber capacitors.
The series targets DC-link applications with SiC power switches in:
Renewable energy converters (solar, wind, electrolyzer, energy storage systems)
Auxiliary drives in traction applications
Industrial motor drives
Key specifications include:
High-temperature operation: +105 °C without derating
High-frequency performance compatible with SiC semiconductors
Modular design
High current density
Self-healing technology
Overvoltage capability
Very low ESL: 8 nH
Dielectric film: ISCC-certified bio-circular BOPP
Housing compliance: UL94 V-0 and EN 45545-2 HL3 R23 fire standards (UL recognition pending)
Detailed electrical ratings:
B25648A1887K003: 1350 V DC, 880 µF, 205 A rated current at +75 °C, 205 kA surge current
B25648A1647K003: 1600 V DC, 640 µF, 190 A rated current at +75 °C, 175 kA surge current
B25648A1477K003: 1800 V DC, 470 µF, 180 A rated current at +75 °C, 150 kA surge current
TDK provides engineering tools for the ModCap series, including a SPICE library, the web-based Capacitor Life and Rating Application (CLARA), and the web-based CAP Thermal for thermal simulation.
