GaN Talk Blog

Brushless DC (BLDC) motors are popular and finding increasing application in robotics, e-mobility, and drones. Such applications have special requirements such as lightweight, small size, low torque ripple, low audible noise, and extreme precision control.  To address these needs, the inverters powering the motors need to operate at higher frequency but require advanced techniques to reduce the resultant higher power loss. Enhancement-mode gallium nitride (eGaN ^®) transistors and integrated circuits offer the ability to operate at much higher frequencies without incurring significant losses. 

Brick DC-DC converters are widely used in data center, telecommunication and automotive applications, converting a nominal 48 V bus to (or from) a nominal 12 V bus. Advances in GaN integrated circuit (IC) technology have enabled the integration of the half bridge and gate drivers, resulting in a single chip solution that simplifies layout, minimizes area, and reduces cost.

This application note discusses the design of a digitally controlled bi-directional 1/16th brick converter using the integrated GaN power stage for 48 V-to-12 V application, with up to 300 W output power, and peak efficiency of 95%.

The standard dimension of the 1/16th brick converter is 33 x 22.9 mm (1.3 x 0.9 inch). The height limit for this design is set to 10 mm (0.4 inch).

Beyond just performance and cost improvement, the most significant opportunity for GaN technology to impact the power conversion market comes from its intrinsic ability to integrate multiple devices on the same substrate. GaN technology, as opposed to standard silicon IC technology, allows designers to implement monolithic power systems on a single chip in a more straightforward and cost-effective way.

Today, the most common building block used in power conversion is the half bridge. In 2014, EPC introduced a family of integrated half-bridge devices which became the starting point for the journey towards a power system-on-a-chip. This trend was expanded with the introduction of the EPC2107 and EPC2108, which integrated half bridges with integrated synchronous bootstrap. In 2018 we further continued the integration path with the introduction of eGaN ICs combining gate drivers with high-frequency GaN FETs in a single chip for improved efficiency, reduced size, and lower cost. Now, the ePower™ Stage IC family redefines power conversion by integrating all functions in a single GaN-on-Si integrated circuit at higher voltages and higher frequency levels beyond the reach of silicon.