SSZT207 December 2020 ISO7741-Q1 , LMG3425R030 , TMS320F2800137 , TMS320F280025C , TMS320F280039C , TMS320F28379D
Cody Watkins
Gallium nitride (GaN) field-effect transistors (FETs) provide drastically improved switching losses and higher power density over silicon-carbide and silicon-based FETs, respectively. These traits can be particularly helpful in high-switching-frequency applications such as digital power converters, where they can help reduce the size of the magnetics.
Designers in the power electronics industry need new technologies and methods to increase performance in GaN systems. C2000™ real-time microcontrollers (MCUs) can help address design challenges when developing modern power-conversion systems using GaN technology.
The adaptability of a digital controller like a C2000 MCU benefits complex topologies and control algorithms such as zero voltage switching, zero current switching or inductor-inductor-capacitor-resonant DC/DC power supplies with hybrid hysteresis control.
A C2000 MCU enables benefits such as:
As I mentioned earlier, driving higher switching frequencies enables a reduction in the size of the magnetics in switching converters, but this reduction can introduce a number of control challenges. For example, in a totem-pole power factor correction topology, reducing the size of the inductor can cause an increased current spike at the zero-crossing point and increase dead-band-induced third-quadrant losses as well. These effects combine to increase the total harmonic distortion (THD) and reduce efficiency.
To address these issues, C2000 real-time MCUs have feature-rich PWMs to enable soft-starting algorithms that smooth out current spikes and achieve better THD. The C2000 MCU also has extended instruction sets, floating-point unit and trigonometric math unit, that can drastically reduce the time required to calculate parameters such as the PWM’s on time. This time reduction also increases the control-loop frequency, which along with the 150-ps resolution of the PWM helps reduce third-quadrant losses.
A C2000 MCU, digital isolation device and GaN FET are all that are necessary to interface the devices, as shown in Figure 1.
A reinforced digital isolator helps suppress transient noise and protects the C2000 MCU. The C2000 MCU provides precise control output using its high-resolution PWM and configurable logic block and enhanced-capture modules to capture all of the GaN FET’s safety, temperature and error-reporting features without the use of external glue logic. The integrated driver in a 600-V GaN FET reduces system design concerns caused by inductive ringing. Combining these devices eliminates the need for external components, reducing overall costs.
Learn more about the advanced features of TI’s GaN FETs in the technical article, “How GaN FETs with integrated drivers and self-protection will enable the next generation of industrial power designs.”
TI C2000 real-time MCUs and GaN FETs work in harmony to provide a flexible and simple solution for modern digital power systems, while still providing cutting-edge features that enable power-dense and efficient digital power systems. Our fully tested and documented reference designs help accelerate development of high-efficiency and high-density digital power systems.