NuAxiSemiconductor trade intelligence

Dual-Side Cooling Comes to 650-V GaN for 800-V AI Data Centers

What happened

Renesas Electronics recently released a 650-V, 20-mΩ d-mode GaN FET built on Gen 4+ technology in an 8×8 mm dual-side-cooled (DSC) PQFN package, part number TP65H020G4PLSGBD, which is sampling now to AI data center OEMs and ODMs with mass production planned for mid-2027. According to Renesas, Gen 4+ offers lower RDS(on) (and smaller size), lower gate capacitance (CGS, CGD) and output capacitance (Coss) than Gen 4, due to incremental improvements in cell design and better specific on-resistance; Gen 6 won't sample until 2027. The device is d-mode, pairing the GaN transistor with an LV silicon MOSFET. The package supports top-side, bottom-side, or dual-side cooling, currently supports 20-mΩ devices, and with future 10- to 15-mΩ devices a single cold plate may suffice. Versus TOLT, the DSC PQFN offers approximately a 57% to 60% reduction in package area in the x-y axis, is about 1 mm tall versus 2.35 mm for TOLT (2.3 mm in the table), has 9% to 10% lower thermal impedance (0.36 °C/W versus 0.4 °C/W), and cuts PCB area of a four-switch power stage by roughly 15% to 25%. In air-cooled tests on a 6-kW, 800-to-48 V IBC demo board running at 650 kHz to 1 MHz, the DSC showed a 0.14% improvement in full-load efficiency, roughly 10+ W of additional power in a 6-kW converter; liquid cooling was not used because samples had just arrived, with liquid-cooled testing as the next step. The DSC 8×8 (with 650-V GaN) is applied on the primary side, with two 3-kW blocks in series each seeing roughly 400 V of the 800-V bus. The primary applications for the DSC package technology are intermediate bus converters taking 800 V DC on the primary side down to 48 V, 12 V, and 6 V. For 800-to-6 V conversion with output currents beyond 3,000 A, Renesas is working with EPC toward a DSC option for LV GaN. Renesas showcased the device as part of its 800-V power solutions at the OCP Global Summit, held October 12–15 in San Jose, California.