On November 3, 2021, ST exhibited a 65W output power high-density power adapter solution at the 3rd Industrial Summit 2021. This solution uses the ST MasterGaN2 power device, together with an ACF topology, synchronous rectification controller, and USB PD protocol and feedback function in one STONE all-in-one controller, to achieve a simplified circuit 65W Gallium nitride fast charging design.
ACF topology is a new type of flyback topology, the traditional flyback topology in the absorption circuit dissipated leakage inductance energy recovery and storage, through the new switch tube control, the stored energy is released as the transformer reverse excitation, to achieve the main switch of zero voltage on. Zero-voltage opening of the main switch tube reduces switching losses and enables designs with high efficiency and high switching frequency.
ST's controller is also in the ES phase, model STONE, in soop 38 package, across the primary stage, with an internally integrated isolated feedback circuit. The STONE controller features a logic signal output that directly drives ST's MasterGaN half-bridge power devices. And built-in synchronous rectifier driver, USB PD protocol function, external necessary power components can achieve highly integrated high efficiency Gallium nitride USB PD power supply design.
ST's STONE all-in-one controller integrates the original edge controller, gallium nitride driver, feedback optocoupler, synchronous rectifier controller and protocol chip of the traditional power supply, and only one controller is required to match the corresponding switch tube inside the power supply. The emergence of the ST STONE controller has effectively simplified the difficulty of power supply development and design, and solved the problem of long and short materials, changing the history of many traditional power supply components.
ST's MasterGaN is a half-bridge Gallium nitride device that integrates two GaN switch tubes and drivers to form a half-bridge device, which is an advanced system-level power package that can easily input logic voltage signals. ST's MasterGaN series are half-bridge construction with built-in 650V potent reinforced Gallium nitride switch tubes that support an operating temperature range of minus 40 to 125 degrees Celsius.
IT's MasterGaN products are half-bridge structures that integrate two 650V enhanced gallium nitride switch tubes and corresponding drivers in a 9*9*1mm QFN package, which can be easily controlled by the MCU controller. Built-in driver integrated interlock function, support enable pin, peripheral components are streamlined.
MasterGaN series products have a total of 5 products, namely MasterGaN1-5, in order to intuitively understand the device parameters, the charging head network will be five product parameters drawn into a chart for easy reference. Three symmetric half-bridges are suitable for LLC architectures, with MasterGaN1 supporting 400W output power, MasterGaN4 supporting 200W, and MasterGaN5 supporting 100W. Two other asymmetric half-bridges are available for active clamp flyback, the MasterGaN2 for 65W power adapter designs, and the MasterGaN3 for 45W designs.
Charging head net summary
ST's STONE ACF controller chip integrates PWM controllers, synchronous rectifier controllers, USB PD protocol functions, and isolated feedback into one, making them ideal for highly integrated and reliable power supply designs. Although this device is still in the ES stage, through the demonstration of the reference scheme, the advantages of the power chip all-in-one have been highlighted.
The MasterGaN series of half-bridge devices used in conjunction with them have a high degree of integration and simple peripheral circuitry, which significantly reduces the threshold for gaN technology applications. Built-in driver, no need for external driver chip half-bridge structure, very suitable for LLC topology and ACF topology of high-power power adapter applications.