FMEA技术在直流-直流变换器设计中的应用

以一种卫星用直流-直流变换器产品为例,介绍了FMEA在产品设计中的应用。针对潜在的故障模式。提出了改进设计的一些基本方法。这为保证直流-直流变换器产品在轨正常工作以及实现其现场可靠性指标提供了重要依据。     

大功率DC-DC变换器可靠性研究与设计

利用IGBT器件作为DC-DC变换器的功率模块,设计了一套电压电流等级为330 V、30A的DC-DC变换器装置。为了提高其可靠性,采用由两台H桥变换器并联的双机热备份设计方案,并对变换器故障时的负载特性进行详细分析,从而提高系统运行稳定性。     

您实际上需要多少个隔离的直流—直流变换器

5V逻辑标准的时代正在过去。含有最新一代的处理器或ASIC的印制电路板组件需要多种电压向逻辑电路供电。这种印制板组件通常需要下述几种电压:为标准逻辑和接口电路供电的5V,为处理器或ASIC供电的3.3V或2.9V,为总线端接器供电的1.2-2.5V。除此之外,通常还需要为通信电路提供±12V或-5V。在计算机或     

航天器DC／DC变换器的可靠性设计

卫星用DC/DC变换器的高可靠和长寿命,是确保其完成飞行使命的基本条件之一.但人们对DC/DC变换器可靠性的认识通常集中在元器件固有质量或产品组装工艺缺陷方面,往往忽略了系统设计(包括技术方案和电路拓扑设计、输入/输出接口设计、环境试验条件适应性设计等)缺陷和电压、电流和温度应力对可靠性的影响.     

基于自激推挽式小型化二次电源的设计

介绍了自激推挽式DC-DC变换器的基本工作原理,给出了实际工作的自激推挽式二次电源的实用电路及主要单元电路的设计方法,利用单变压器设计出＋10V和-10V两路输出的二次电源,在设计中通过选择电流反馈型电路,消减了开关管导通和关断时出现的电流尖峰,通过用MOSFET代替晶体管避免磁通不平衡。最后对电路进行了实验测试,验证了二次电源的稳定性和可靠性,实现了数模混合电路系统供电电路的小型化.     

50 MHz dual-mode buck DC-DC converter

A 50 MHz 1.8/0.9 V dual-mode buck DC-DC converter is proposed in this paper. A dual-mode control for high-frequency DC-DC converter is presented to enhance the conversion efficiency of light-load in this paper. A novel zero-crossing detector is proposed to shut down synchronous rectification transistor NMOS when the inductor crosses zero, which can decrease the power loss caused by reverse current and the trip point is adjusted by regulating IBIAS (BIAS current). A new logic control for pulse-skipping modulation loop is also presented in this paper, which has advantages of simple structure and low power loss. The proposed converter is realized in SMIC 0.18 μm 1-poly 6-metal mixed signal CMOS process. With switching loss, conduction loss and reverse current related loss optimized, an efficiency of 57% is maintained at 10 mA, and a peak efficiency of 71% is measured at nominal operating conditions with a voltage conversion of 1.8 to 0.9 V.     

DSP控制移相全桥DC-DC变换器的研究与设计

随着电力电子技术的日渐成熟,开关电源越来越朝着小型化,高效化的方向发展.DC-DC变换器是以移相全桥为主电路,其核心的数字化控制是DSP来实现的.移相全桥DC-DC变换器具有开关损耗小,效率高和输出电流纹波小等优点.本文内容包括硬件电路设计、软件的实现及通信协议等.     

The design and experimentation of the new cascaded DC-DC boost converter for renewable energy

After renewable energy generated, a direct current value is converted to a direct current value at another level for a power electronics and power system application that is often considered. In this article, the design and application of a new generation multi-time cascaded DC-DC converter are discussed. The dc-to-dc converter is three-levels, and the switches for each step have a working time and a non-working time. Mathematical models are established depending on the relationship between current and voltage according to the operating and non-operating states of the switches at each stage. After these mathematical models are creating, the new generation multi-timed DC-DC converter is run in Matlab Simulink and simulation results are validated in experimentation. The output voltage and inductor current are observed with a scope. Then, the results from the proposed converter are compared with the results of the traditional converters. The results show the effectiveness of the proposed dc-dc converter.     

数字电位器在DC-DC变换器中的应用

在升压和降压DC—DC变换器中，可以用数字电位器的工作达到对输出电压进行校准和调节的目的。     

驱动式DC-DC变换器设计

为了对直流电压进行变换,采用DC-DC技术,设计输出电压可调的直流电压变换器。变换器包括驱动式方波电路、功率管组成的调整电路、比较采样电路和滤波电路。在multisim软件环境下进行仿真,并在实际电路进行测试,获得的结果满足设计要求。实验证明,升压变换器可实现输入5 V直流电压,输出12 V直流电压;降压变换器可实现输入12 V直流电压,输出5 V直流电压;具有良好的直流变换功能。     

混合动力船舶双向DC-DC变换器的研究与设计

针对全桥双向DC-DC变换器Buck和Boost两种模式参数设计要求不同的问题,提出了一种"占空比-变压器-电感"匹配设计法。对全桥双向DC-DC变换器的两种工作模式分别进行建模,设计了闭环控制系统,Buck模式的闭环控制系统保证了动力电池恒压充电;Boost模式的闭环控制系统保证了母线电压恒定。根据混合动力船舶的特点设计了双向DCDC变换器,仿真实验验证了所设计的双向DC-DC变换器控制系统和控制策略的正确性,保证了分别处于两种工作模式时输出端电压稳定。     

Design of a total-dose radiation hardened monolithic CMOS DC-DC boost converter

This paper presents the design and implementation of a monolithic CMOS DC-DC boost converter that is hardened for total dose radiation.In order to improve its radiation tolerant abilities,circuit-level and device-level RHBD(radiation-hardening by design) techniques were employed.Adaptive slope compensation was used to improve the inherent instability.The H-gate MOS transistors,annular gate MOS transistors and guard rings were applied to reduce the impact of total ionizing dose.A boost converter was fabricated by a standard commercial 0.35μm CMOS process.The hardened design converter can work properly in a wide range of total dose radiation environments,with increasing total dose radiation.The efficiency is not as strongly affected by the total dose radiation and so does the leakage performance.     

A high-efficiency DC-DC buck converter for sub-2×VDD power supply

This paper presents a DC-DC step-down converter, which can accommodate the range of power supply voltage from VDD to sub-2×VDD. By utilizing stacked power MOSFETs, a voltage level converter, a detector and a controller, the proposed design is realized by a typical 1P6M CMOS process without using any high voltage process to resolve gate-oxide reliability and leakage current problems. The core area of the proposed design is less than 0.184 mm², while the power supply range is up to 5 V. Since the internal reference voltage is 1.0 V, it can increase the output regulation range. The proposed design attains very high conversion efficiency to prolong the life time of battery-based power supply. Therefore, it can be integrated in a SOC (system-on-chip) to provide multiple supply voltage sources.     

Load adaptive start-up scheme for synchronous boost DC-DC converter

This paper presents a load adaptive soft-start scheme through which the inductor current of the synchronous boost DC-DC converter can trace the load current at the start-up stage. This scheme effectively eliminates the inrush-current and over-shoot voltage and improves the load capability of the converter. According to the output voltage, the start-up process is divided into three phases and at each phase the inductor current is limited to match the load. In the pre-charge phase, a step-increasing constant current gives a smooth rise of the output voltage which avoids inrush current and ensures the converter successfully starts up at different load situations. An additional ring oscillator operation phase enables the converter to start up as low as 1.4 V. When the converter enters into the system loop soft-start phase, an output voltage and inductor current detection methods make the transition of the phases smooth and the inductor current and output voltage rise steadily. Effective protection circuits such as short-circuit protection, current limit circuit and over-temperature protection circuit are designed to guarantee the safety and reliability of the chip during the start-up process. The proposed start-up circuit is implemented in a synchronous boost DC-DC converter based on TSMC 0.35μm CMOS process with an input voltage range 1.4-4.2 V, and a steady output voltage 5 V, and the switching frequency is 1 MHz. Simulation results show that inrush current and overshoot voltage are suppressed with a load range from 0-2.1 A, and inductor current is as low as 259 mA when the output shorts to the ground.