DC-DC
48 V is being adopted in many applications including AI systems, data centers, and mild hybrid electric vehicles. However, the conventional 12 V ecosystem is still dominant and so the need of a high power density 12 V to 48 V boost converter is required.
Modern displays typically require a low power boost converter. In this application, the screen intensity is low to moderate and the converter operates at light load most of the time, so the light load efficiency is very important.
This application note presents the design of a 1 kW, 4:1 conversion ratio, eGaN FET-based LLC resonant converter in the 1/8th power brick size for the 48 V server applications. The EPC9149 [5] converter module achieves 97.5% peak efficiency and 96.7% full-load efficiency.
This application note discusses the design of a 1.5 kW, two-phase 48 V/12 V bi-directional converter using automotive qualified GaN FETs that operates with 95% efficiency. The heatsinking capability can be considered infinite since this will ultimately function inside a vehicle with the unit mounted to the chassis. The design of this converter is scalable to 3 kW by paralleling two converters.
砖式DC／DC转换器广泛用于数据中心、电信和车载应用，可将标称48 V总线转换为标称12 V总线（或从标称12 V总线转换）。 氮化镓集成电路技术的迅猛发展集成了半桥器件和栅极驱动器，从而实现单芯片解决方案，可简化布局、减小面积并降低成本。
As computers, displays, smart phones and other consumer electronics systems become thinner and more powerful, addressing the challenge of thinning the power converter and getting more power out of limited space without increasing the surface temperature increases in demand. This application note will look into designing a 44 V to 60 V input, 12 V to 20 V, 12.5 A output, thin DC/DC power module with low temperature rise using eGaN FETs in the simple and low-cost synchronous buck topology.
Brick DC-DC converters are widely used in data center, telecommunication and automotive applications, converting a nominal 48 V to a nominal 12 V distribution bus among other output voltages. The main trend has been towards higher power density given the form factor is fixed. This application note discusses the design of a digitally controlled 1/16th brick converter using GaN FETs for a 48 V to 12 V, 9 V, 5 V application, with up to 25 A output current, 300 W output power, a peak efficiency of 95.8%, and maximum power density of 730 W/in3.
Over the past decade, DC-to-DC power modules in datacom, telecom, and consumer electronics systems demand more power with increasing limitations on space and volume, requiring ultra-thin and highly efficient solutions. The multi-level converter is an exceptional candidate to shrink the size of the magnetic components and achieve high efficiency in a compact solution.
The rapid expansion of the computing and telecommunication market is demanding an ever more compact, efficient and high power density solution for intermediate bus converters. The LLC resonant converter is a remarkable candidate to provide a high power density and high efficiency solution. eGaN FETs with their ultra-low on-resistance and parasitic capacitances, benefit LLC resonant converters by significant loss reduction that is challenging when using Si MOSFETs.
运算和通信市场的迅速扩展要求中间总线转换器采用更紧凑、更高效和具有更高的功率密度的解决方案。LLC谐振转换器是提供具备高功率密度、高效解决方案的优秀选择。LLC谐振转换器受惠于具有超低导通阻抗和寄生电容的氮化镓场效应晶体管（eGaN FET），可大大降低功耗，高功耗是采用硅MOSFET的转换器的一大挑战。
Single-phase buck converter can work efficiently at output currents up to 25 A, but the power efficiency drops significantly at higher currents. A compact, cost effective, high-power and high-efficiency 48 V to 12 V buck converter, suitable for high-power computing and telecommunication applications, can be achieved by employing eGaN FETs such as EPC2045 in a multiphase topology.
采用氮化镓场效应晶体管(eGaN FET)，例如EPC2053，可实现最微型、最具成本效益、最高效及可提供25 A 的输出电流的非隔离型48 V 转到5-12 V 转换器，适用于高效运算及电信应用。EPC9093开发板被配置为同步降压转换器，主要功率级的占板面积只是10毫米x9毫米，与等效硅元件相比，其体积最少缩小了两倍，而且输出电压可在5 V至12 V范围内。
采用氮化镓场效应晶体管（eGaN® FET），例如EPC2045器件，可实现适用于高效运算及通信应用的最微型、最具成本效益及最高效的非隔离型48 V – 12 V 转换器。EPC9205被配置为一个同步降压转换器，当工作在48 V输入电压、12 V 输出电压及10 A负载条件下，可实现1400 W/in3 功率密度、5 V至12 V的输出电压范围及提供14 安培输出电流。
采用单片半桥式eGaN集成电路（例如EPC2111）可以实现最微型、最具成本效益及最高效率的非隔离型12 V–1 V负载点转换器，适用于高效运算、比特币挖矿及电信等应用。EPC9204被配置为同步降压转换器，功率密度可达1000 W//in3 及可发送12安培电流。
激光雷达（Lidar）
激光雷达（Lidar）是一种远距感测技术，从感测器发射光脉冲，并记录反射光线的时间，从而映射物件的位置及距离。氮化镓场效应晶体管具备超高性能，而且它采用芯片级封装，因此具有超低电感，使得它们成为脉冲激光驱动电路最理想的开关器件。
电机驱动器
无刷直流电机（BLDC）非常受欢迎，其应用越来越多，包括机械人、电动车及无人机。这些应用有特别要求，包括轻型、小尺寸、低转矩脉动及精准控制。对电机供电的逆变器如果要符合这些要求， 必需在更高的频率下工作，但功耗会更高，所以需要采用先进的技术，降低功耗。
AC/DC
随着各种日新月异的应用的发展，例如云计算、可穿戴设备、机械学习、全自动驾驶车辆及物联网，促使全球面对如何处理进一步庞大的数据及与日俱增的数据中心和功耗的要求 [1、2]。效率、功率密度及成本对AC/DC开关电源供电非常重要，这些因素推动了基于氮化镓场效应晶体管（eGaN FET）的创新解决方案的出现，从而实现基于超高效的前端PFC整流器的解决方案 – 这是本应用笔记的重点。
设计
与等效硅基方案相比，由于基于氮化镓场效应晶体管（eGaN FET）的功率转换系统可实现更高的效率、更高的功率密度和更低的整体系统成本，它使得功率电子元件的生态系统日益增长，包括可提升eGaN FET性能的栅极驱动器、控制器和无源元件。
eGaN FETs are capable of switching much faster than Si MOSFETs, requiring more careful consideration of PCB layout design to minimize parasitic inductances. Parasitic inductances cause higher overshoot voltages and slower switching transitions. This application note reviews the key steps to design an optimal power stage layout with eGaN FETs, to avoid these unwanted effects and maximize the converter performance.
EPC’s wafer level chip-scale packaging such as the Land Grid Array (LGA) and Ball Grid Array (BGA) packages shown in figure 1, has enabled a new level of performance in power conversion. Many of these parts use a fine pitch down to 400 μm which means a proper PCB footprint design is essential for consistent and reliable assembly of the GaN device. Here are the guidelines of designing a correct footprint for any EPC part working from the datasheet.
EPC公司的创新封装－芯片级、基板栅格阵列（LGA）及球栅阵列（BGA）封装（如图1所示）推动功率转换实现更高的性能。要发挥氮化镓技术的高效性能，必需使用合适的组装技术。以下是如何手工组装这些场效应晶体管或集成电路的指南。
eGaN FETs and ICs enable very high-density power converter design, owing to their compact size, ultra-fast switching, and low on-resistance. The limiting factor for output power in most high-density converters is junction temperature, which prompts the need for more effective thermal design. The chip-scale packaging of eGaN also offers six-sided cooling, with effective heat extraction from the bottom, top, and sides of the die. This application note presents a high-performance thermal solution to extend the output current capability of eGaN-based converters.
随着基于eGaN FET的转换器的电路性能不断提高，对电路性能的测量的要求也在提升。 本文比较各种测量技术及对应用中的高性能氮化镓场效应晶体管的性能进行评估。