单芯片高效率降压DC-DC芯片设计

介绍了一种单芯片DC-DC转换器IC设计与电路实现,其特点是宽负载电流条件下具有较高效率.芯片的设计和仿真基于上华0.6 μm双阱、混合信号CMOS工艺.芯片的工作电压范围为2～5 V,可以使用于一般的电池供电设备.对提高芯片效率的方法以及效果进行了详细的讨论分析.仿真结果表明,芯片可以产生稳定的1.8 V输出电压,并提供大于500mA的输出电流,而纹波电压却小于5 mV.芯片可以获得93.8%的最大转换效率,而且在5～500 mA的负载电流范围内,效率始终高于86.2%.     

使用两种频率补偿技术的低压差稳压器设计（英文）

介绍了一款具有两种频率补偿技术的低压差(LDO)线性稳压器。在LDO误差放大器的设计中,同时采用嵌套密勒补偿技术和具有可变负载的动态密勒补偿技术,确保LDO在负载电流变化60mA范围内的稳定性。该LDO采用联华电子公司(UMC)0.11μm CMOS工艺实现,所设计的LDO输入电压1.5~3.3V,负载最大电流60mA,输出电压稳定在1.23V。芯片测试结果表明,当负载电流从1mA突变为60mA或者从60mA突变为1mA时,LDO的输出稳定时间小于30μs,且输出电压变化小于12mV。在3.3V的输入电压下,LDO的静态电流为50μA,且在满负载变化时输出电压的变化仅有18mV。     

一种应用于硅基OLED微显示驱动芯片的负压DC-DC变换器的设计

设计了一款应用于硅基OLED微显示驱动芯片的Cuk型DC-DC变换器,用于给硅基OLED的公共阴极提供负电压,输出电压范围为0~-4V,可以实现动态可调。Cuk变换器采用单周期和III型补偿的混合控制方式,使电路获得了良好的抗输入扰动性和负载调整率。该变换器使用0.35μm CMOS工艺模型进行设计,工作在2 MHz开关频率。仿真结果显示,在150mA负载跳变时,瞬态恢复时间为24μs,过冲电压为33.47 mV,同时负载调整率为0.003 mV/mA,输出电压的纹波小于5mV。     

用于AM-OLED的高性能DC-DC变换器设计

设计了一款用于AM-OLED驱动控制系统的高性能DC-DC变换器.该变换器可同时提供正压和负压输出.在误差放大器中通过引入负反馈,扩展了线性工作范围,减小了输出纹波,同时引入低压隔离电路,提高了系统启动速度.在比较器中采用轨对轨差动输入级,提高了系统动态响应速度,减小输出纹波.在PWM驱动电路中采用低功耗驱动电路,减小了系统功耗,提高了转换效率.采用0.16μm HV CMOS工艺对电路进行设计和Spice仿真,仿真结果表明,在工作频率为1.5MHz,输入电压在2.5~4.5V范围变化时,正向输出电压稳定在4.6V,负向输出电压可通过改变反馈电阻在-2.4~-6.4V范围内调节,输出纹波小于25mV,负载电流最高可达250mA,转换效率达85%以上,均满足AM-OLED驱动控制芯片的要求.     

高稳定度和宽电源电压范围晶体振荡器芯片设计

基于0.6μm CMOS混合信号工艺设计了一款高稳定度、宽电源电压范围的晶体振荡器芯片。该芯片片内集成具有优异频率响应的振荡器电容和反馈电阻,只需外接石英晶体即可提供高稳定时钟源。测试结果表明:芯片最高工作频率可达40MHz;在振荡频率12MHz、负载电容15pF、电源电压从2.7V到5.5V变化时其频率随电源电压变化率小于1×10-6;电源电压为5V时芯片消耗总电流小于4mA。     

一种应用于OLED显示驱动芯片的CMOS升压型PFM DC-DC转换器设计

由于DC-DC芯片工作模式的多样性,电源转换器的系统结构有多种不同选择。为了电源模块的安全可靠,往往需要多种保护电路模块。文中从系统的角度,阐述了适合于OLED显示驱动电路的PFM工作模式的升压DC-DC电源转换器的原理。在此基础上,设计了一种应用于OLED驱动电路芯片的升压DC-DC电路。当输入电压为2.4～4.2V时,输出电压可以达到15V,负载电流最大可以达到50mA,纹波电压小于200mV。这个设计可以与OLED驱动芯片集成在一起,实现OLED驱动芯片和电源管理芯片的集成。     

一种快速瞬态响应无片外电容LDO

针对无片外电容LDO,在误差放大器与功率管之间添加缓冲器,采用频率补偿的方法,提高了环路稳定性。通过检测负载瞬态变化引起的误差放大器输出电压变化,增加对功率管栅极电容的充放电电流,提升了系统的快速瞬态响应能力。基于TSMC 0.18 μm标准CMOS工艺,设计了一种输入电压范围为1.92~3.60 V、输出电压为1.8 V的LDO。结果表明,负载在1 μs内从0变化到100 mA时,输出最大下冲电压为37.2 mV,响应时间为1.12 μs;负载在1 μs内从100 mA变化到0时,输出最大过冲电压为40.1 mV,响应时间为1.1 μs。     

基于数字PID补偿的降压型DC-DC控制器

设计了一个基于数字PID控制,可为低压系统提供稳定电源的多相位降压型DC-DC控制电路,包括flash ADC、数字PID控制器;并设计了一种新的基于延时单元/计数器的数字PWM电路,实现了一个降压型控制器。电路使用3.3 V CMOS工艺设计,芯片面积为0.16 mm2,输入电压3 V,输出电压1.25 V,负载电流最大800 mA,纹波小于10 mV,开关频率1 MHz,效率最高达到90%。     

一种简洁高效的单片DC-DC转换器软启动电路

设计了一款用于单片集成DC-DC:转换器的简洁而高效的软启动电路,该电路消除了芯片启动时的过压冲击并有效地降低了浪涌电流.在误差放大器一输入端采用不同时段接入若干电容的方法使输出电压分段线性上升.Spectre仿真表明,对一个输入电压为5 V,输出电压为2.5 V的降压芯片在电感峰值电流为330 mA时,浪涌电流从830 mA降低到550mA,并且持续时间特别短,同时过充电压被完全消除.此电路简单可行,适用于各种DC-DC降压芯片.     

一种多模式高效率单片同步BUCK型DC-DC变换器

提出了一种可在两种控制模式下工作的峰值电流模式单片Buck型同步DC-DC变换器,在突发模式(Burst mode)下应用了动态部分关断技术(DPSS),使整个芯片的静态电流降低到63.5μA,并在宽负载范围内都有较高的效率.提出了一种适用于两种控制模式的电流检测和斜坡补偿叠加电路,提高了动态响应速度.该变换器采用0.8μm汉磊BCD工艺模型仿真,验证了设计的正确性.在4.2V转换1.5V的条件下,突发模式时,转换效率为84%;PWM模式时,转换效率为75.8%.在4.2转换到3.3V时,芯片能达到95.2%的最高转换效率,此时负载电流150mA.     

消费品工业信息化与工业化融合的推进策略

消费品工业是重要的民生产业,是国民经济的重要组成部分。面临日益复杂多变的经济环境,以及当前资源环境约束日益趋紧的形势,迫切需要将信息化要素注入到消费品工业的关键环节,大力推进消费品工业信息化与工业化融合,以促进消费品工业的调整振兴。本文主要从当前我国消费品工业信息化与工业化融合的现状出发,深入分析存在的问题,结合国家推进信息化与工业化融合的措施,提出消费品工业信息化与工业化融合的推进策略。     

基于多Agent的消费者需求代理系统分析与研究

从电子商务环境下不同消费者生命周期阶段的消费者需求特点出发,充分考虑消费者的个人偏好,以消费者需求为导向建立了基于多Agent的消费者需求代理系统,充分满足不同生命周期阶段的消费者个性化需求,提出了需求代理工作流程。     

Consumer Vehicle Telematics — An Emerging Market Where Web Services

This paper examines how Web Services can be used to provide a shared infrastructure in an emerging area of consumer communications, namely consumer vehicle telematics. The paper reviews the key advantages which Web Services offer from a service provider's viewpoint — namely openness, reuse and ease of integration with legacy systems. The paper then goes on to examine why the consumer vehicle telematics industry is an area where point solutions have been developed. It then explores why legislation, changes in industry dynamics and the growing use of electronics in vehicles make the use of Web Services, in the software platform supporting the applications, an attractive proposition. Using a scenario-driven approach, it is shown how Web Services can be employed to provide reusable components which can make applications available for vehicle manufacturers, vehicle dealers, legislators and third-party service providers. These applications can be used to provide information to drivers, occupants and vehicles themselves. The paper also presents a brief review of the emerging competitive environment. This revised version was published online in July 2006 with corrections to the Cover Date.     

Can the military use commercial wireless signal processing technologies to reduce size, weight and power in radio devices? [Trends in DSP]

This paper discusses if military can adopt commercial air interface standards and leverage the technology developed for the consumer wireless market to manage size, weight, and power in defense communications. The differences in operating requirements that drive the architectures of commercial and defense wireless systems are presented: frequency band of operation, security constraints, and operation in a tactical environment     

电子商务环境下的消费者行为态度研究

针对消费者涉入程度高的计算机产品,通过问卷设计获得统计数据建立消费者行为态度模型,通过对模型的假设检验进一步说明在B2C电子商务环境下,态度行为理论和技术创新扩散理论仍然有效,消费者网上购买计算机的行为意图和态度之间存在显著的相关性。对于其余占消费者可支配收入比例大的商品与服务,模型仍然具有较高的应用价值。     

A fault diagnosis system for the connected home

The connected home of the future, in which all consumer appliances in a home are networked together, is close to becoming the connected home of today. This article explores the role of fault diagnosis in such an environment and explains how agent technology may be applied. The article outlines the need for future standards that can maximize the benefit of a shared diagnostic system.     

Users’ perspective on the adoption of e-learning in developing countries: The case of Nepal with a conjoint-based discrete choice approach

The traditional approach of teaching and the learning environment has shrunken the information access capability and widened the knowledge gap, rather than preparing for the global competitive market. It can be minimized by integrating technology in education by exploiting the technology effectively. To date, integration of technology in education is often done through forced adoption without considering the perception of the real consumer. Using conjoint-based discrete choice modeling, this study aims to identify the preference for e-learning in a school environment, providing key implication for effective reformation of education incorporating the demand side for the optimum outcome. The identified preferences will allow the government to more effectively map and mobilize resources for the use of technology in the learning environment.     

基于8位CPU核的混合信号SoC验证技术

教模混合系统芯片（SoC）验证技术是SoC设计中的一个难点。文中基于8051核总线构建一个8位SoC设计验证平台,利用NC-SIM的数字仿真环境和Hsim的模拟仿真环境相结合的方式,对整个混合电路进行验证。该验证环境是建立在IP复用规范的基础上,具有很强的可移植性。同时该环境使用的激励文件和IP可以被一起设计复用,因此在仿真精度和仿真速度都能够得到保障的前提下,可以大大减轻电路混合验证的工作量。通过该混合验证环境,成功设计一个8位SoC芯片,功能和性能指标都达到用户要求。     

Digital rights management in consumer electronics products

In the current consumer electronics (CE) environment, we see many activities in content protection and digital rights management (DRM) which could lead to a situation with many standards and unnecessary limitations on the flow of content over various devices. As a result, the main challenge in the CE environment is to develop DRM solutions that allow interacceptable exchange of content that is acquired via any of the main distribution channels to the customer, being discs media, broadband, broadcast, and wireless. To achieve this, several important architectural and research issues have to be resolved. These solutions can only emerge through tight cooperation between the stakeholders and through the development of open standards.     

More on China [technological revolution]

This paper provides a list of references relating to the technological advances in China in the fields of Internet and censorship, consumer electronics, intellectual property, transportation, environment and conservation, and semiconductors.