TDK Boosts DC Voltage of SMT Gate Driver Transformers
High-frequency power conversion systems have long demanded compact isolation transformers that can handle higher voltages without compromising performance. TDK has introduced an extension of its EPCOS InsuGate series of surface-mount gate drive transformers. These new variants are rated for a DC working voltage up to 1000 V. The components now meet the IEC 61558-1/2-16 standard for basic insulation and seek to enable space-saving gate driver architectures for full-bridge inverter modules.
The extended TDK EPCOS InsuGate Series. Image used courtesy of TDK
EPCOS InsuGate Series
The updated InsuGate components support a DC working voltage greater than 1000 V, a significant step from prior generations. TDK claims that the compact 13.85 x 10.5 x 9.2 mm surface-mount footprint reduces PCB area consumption by roughly 30% compared to legacy designs offering similar insulation strength. The triple-insulated winding structure is implemented on a MnZn ferrite core and achieves basic insulation compliance under IEC 61558-1/2-16.
According to the datasheet, the components provide a 75 µH nominal inductance and exhibit stable performance up to +150°C. They feature a typical coupling capacitance of 4 pF, which aligns them with fast-switching semiconductor applications, such as IGBT and SiC gate drivers. Meanwhile, electrical robustness is reinforced by a partial discharge extinction voltage of ≥1.2 kV, a reinforced insulation rating of 300 V (AC), and a high-voltage test rating of 3 kV (AC) for 60 seconds.
Product dimensions. Image used courtesy of TDK
TDK validated the transformers’ mechanical durability through extended vibration testing according to AQG 324 on standard Eurocard PCBs. The components are AEC-Q200 Rev. E qualified, and SPICE simulation models are also available to support early-stage design integration.
Understanding Triple-Insulated Windings
Triple-insulated wire (TIW) technology lets transformer manufacturers meet safety standards without additional insulation barriers. In TIW construction, each wire is coated with three independent insulation layers. This configuration adds redundancy so that the remaining layer can maintain electrical isolation even if one or two layers degrade or suffer mechanical stress. Regulatory standards such as IEC 61558 recognize TIW as a valid substitute for physical separation barriers, significantly simplifying transformer design and reducing component size.
Triple-insulated wire. Image used courtesy of Thermosleeve USA
TIW’s benefits become particularly important in gate drive transformers, where compact form factors and high isolation voltage requirements coexist. Traditional isolation methods often involve multiple insulation tape layers or encapsulation, which increases transformer dimensions and reduces thermal efficiency. TIW eliminates these issues while improving reliability in environments subject to vibration and thermal cycling.
In high-frequency applications such as IGBT and SiC gate driving, maintaining low interwinding capacitance is equally vital. TIW allows designers to optimize winding geometries that keep parasitic capacitance low, thus preserving fast transient response and reducing EMI. This directly contributes to improved switching performance and overall system efficiency in power conversion circuits.
Isolation Solutions for Power-Dense Applications
TDK’s expansion of the InsuGate SMT transformer series to support 1000 V DC working voltage could open new possibilities for compact, high-reliability designs in power electronics. With enhanced insulation integrity, low parasitic elements, and automotive-grade qualification, these transformers offer a powerful solution for designers working on high-frequency gate driver circuits in electric vehicles, renewable energy systems, and industrial motor drives.
The components are available now through TDK’s global distribution network.
