基于单片机的智能手机充电器的设计(英文版)

n更多企业学院： 中小企业管理全能版183套讲座+89700份资料总经理、高层管理49套讲座+16388份资料中层管理学院46套讲座+6020份资料国学智慧、易经46套讲座人力资源学院56套讲座+27123份资料各阶段员工培训学院77套讲座+ 324份资料员工管理企业学院67套讲座+ 8720份资料工厂生产管理学院52套讲座+ 13920份资料财务管理学院53套讲座+ 17945份资料销售经理学院56套讲座+ 14350份资料销售人员培训学院72套讲座+ 4879份资料n更多企业学院： 中小企业管理全能版183套讲座+89700份资料总经理、高层管理49套讲座+16388份资料中层管理学院46套讲座+6020份资料国学智慧、易经46套讲座人力资源学院56套讲座+27123份资料各阶段员工培训学院77套讲座+ 324份资料员工管理企业学院67套讲座+ 8720份资料工厂生产管理学院52套讲座+ 13920份资料财务管理学院53套讲座+ 17945份资料销售经理学院56套讲座+ 14350份资料销售人员培训学院72套讲座+ 4879份资料Improvements in Battery Charger ICs Keep Pace with Rapid Increases in Mobile Handset CapabilitiesIn the era of global wireless connectivity, almost nothing is more important than keeping a smart phone or mobile Internet device charged. Expanding features on the constantly improving portable and handheld device create a major challenge for designers of battery charger ICs. High resolution screens and larger memories combine with new capabilities to tax the battery, requiring battery charger technology that is not only more efficient but also capable of managing power distribution. Optimizing power consumption to prolong battery life has always been a driving force in handheld power management. However what is changing are the efficiency expectations for charging handheld devices when they are plugged into the wall. The latest generations of device designs are using high-efficiency switching chargers in place of traditional linear chargers. Customers today continue to demand shorter charge cycles when charging their battery. Beside higher efficiency with respect to the conventional linear chargers, one of the great advantages of using switching chargers solution is the capability to boost the charge current from what supplied by the source. This is especially important when powering off of a USB port where the current available might be limited to less than 500mA. Higher charge currents equate to shorter charge cycles thus satisfying customer expectations.There are two kinds of battery chargers used in most handhelds now linear chargers and switching devices. Linear chargers have a longer history. They have typically provided a relatively efficient, simple way to charge portable devices, creating minimal noise without many external components. But as portable devices become more complex and add layers of new features, they need higher battery capacity. Linear chargers present liabilities due to power dissipation, which become clear if a user wants to charge a device while using at the same time. The heat generated while simultaneously using and charging can damage the system or battery. Not a good outcome. The alternative is a switching device, or switch mode battery charger IC, that can deliver higher current levels to a battery while requiring as little power as possible. Historically, there have been some noise issues with these kinds of ICs. In addition, some early generations of switch mode devices have required several external components. However, the benefits of the switched mode battery topology are clear. They include higher efficiency and lower power dissipation, along with fast charging cycles. These devices also are capable of charging from higher input voltages, which allows the use of lower cost unregulated adapters. They can increase the charging current from current restricted sources. The noise from switching chargers usually comes during light load operation, particularly during preconditioning. As it decreases, many switching chargers move into an operation known as pulse skipping. In pulse skipping, the PWM frequency changes asynchronously. There have been battery charger ICs developed that supply high charge current with minimal thermal impact to the system using a switching charger, then switch into a linear charger during low current charging modes to minimize noise. This type of PWM switch mode charger with a linear mode has been a good development, providing high efficiency at the full constant current (fast charge) rate. The switching charger controls large constant current charge (up to 2A) with a PWM switching regulator. It automatically moves to linear mode while the battery is preconditioning and near the end of constant voltage taper charge mode, which lowers the noise while the switch mode speeds up charging. Once the charge current level dips below 300 mA, the linear mode kicks in completely and noise generated by the switching converter is eliminated. But now there are further advances. For example, an ideal solution for new handhelds is a complete charger for single cell Li+/ Polymer batteries with up to 1A charge current and advanced indication capabilities for full charge system monitoring. USB Compliant 100mA/500mA charge current settings are beneficial as are programmable pre-charge and fast charge. Many products also include battery temperature monitoring, which ensures safe charging. Companies such as Intersil are leading the development effort for new generations of charger ICs. These fully integrated solutions serve compact applications and provide charge controllers for higher power applications. Charge voltage accuracy is now at 0.5 percent, an improvement over just a few years ago, when an accuracy rating of 1 percent was considered good. Switching frequencies are up to 3 MHz and new switching chargers now provide up to 2A charge current, with one recent example being the ISL9220, which is suitable for both 1 and 2 cells Li Ion applications. In addition, new designs restrict leakage - there is no less than 0.5uA typical leakage current off the battery when no input power is attached. These improvements also have become available in smaller and smaller packages, such as 4 x 4mm QFNs or 2 x 2mm CSPs, which save real estate in space-constrained handheld equipment. The latest battery charger ICs also are able to monitor the input voltage, the battery voltage, and the charge current. When any of the three parameters exceeds specific limits, the IC turns off an internal N-channel MOSFET to remove the power from the charging system to the battery. This kind of flexible efficiency is another of the improvements now available in these important devices, which are vital to the continuing growth and feature set expansion of mobile, handheld products.【作 者】Marino, Giampaolo; Schmitz, Tamara【刊 名】Electronic Component News【出版日期】2010【卷 号】Vol.54【期 号】No.1【页 码】16DESIGN AND IMPLEMENTATION OF A MICROCOMPUTER 8051 SYSTEM POWERED BY DUAL BATTERIES CHARGED BY SOLAR CELLSAbstractSingle-chip microcomputer systems are becoming increasingly popular in current control and information applications. However, due to their battery energy limitations, these systems have a very restricted operation time or recharge cycle if a single rechargeable battery supplies their power. We propose a design and implementation for the software and hardware of a microcomputer 8051 system powered by a dual rechargeable battery that is charged by solar cells. From a feasibility analysis of the queueing model for the stochastic charging and discharging process of the dual battery system, due to the random characteristics of weather conditions and users operational behavior, we confirm that the average operation time for this model can be much longer than that of a single rechargeable battery power supply. The experimental results of our design also show approximately the same results as our model. With a two-thirds utilization ratio, we can obtain an average operation time four times as long in theoretical results, and three and half times as long in experimental results than with a single rechargeable battery power supply. In addition, the technology trend shows that the power consumption rate for a typical microcomputer system is decreasing and the power generation efficiency for typical solar cells is increasing. Hence, solar cells as the power charging sources for a microcomputer 8051 system supplied by a dual rechargeable battery can be feasible in the near future.Over the past few years, microcomputer system design researchers have been working with different levels of low-power technology. In terms of system, circuits, and device power saving, the results show that every year from 1992 to 1997 the average power consumption of a microcomputer computer decreased more than 20%,and from 1998 to 2001 it decreased by 10%.Reducing power consumption is important because of its potential to extend the recharge period of portable information applications. The longer the battery operation time before a recharge is needed, the more convenient it is for mobile users to operate a portable microcomputer system.Eventually, the power consumption of a single-chip microcomputer system will be small enough to be supplied or recharged by other power sources. One of the proposed power sources is mechanical vibration. Among others, we previously proposed solar cells that can be used as power supply sources. Although current mc-Si solar cell power generation efficiency is not high enough, their efficiency increased from 14.2% to 16.8%from 1990 to 1997.This improvement can reduce the gap between the charging and discharging rate of the power supply of a microcomputer system, so the probability of power exhaustion within a certain operational time is reduced each year.To prolong the battery operation time before recharging, in this article we present the software and hardware module for a single-chip microcomputer 8051 system with a dual battery charged by solar cells. Based on its design and implementation, this work also presents the estimation for power exhaustion probability and the experimental measurement for operation time that depends on the power generation efficiency of solar cells and the power consumption rate of a microcomputer. In addition, due to the overlapping of the charging and the discharging period, if the ratio between the charging and discharging rate is two thirds, then the operation time can potentially be prolonged four times in comparison with a single rechargeable battery.The rest of this is organized as follows. In Section 2, the technology trends with respect to the power consumption of a microcomputer and the power generation efficiency of solar cells are discussed. In Section 3, the queueing model for the stochastic charging and discharging behavior for the dual rechargeable battery in a single-chip microcomputer system is presented. In addition, the feasibility estimation for the dual rechargeable battery in a single chip microcomputer system is given. In Sections 4 and 5, the design and implementation of the software and hardware modules for this system are provided. In Section 6, the experimental results of this system are given. The last section presents conclusions.7. ConclusionsWe have presented the design and implementation of a microcomputer 8051 system powered by dual batteries charged by solar cells. The hardware components used are very common and are of low cost. The control program designed uses a common variety of assembly language. The experimental system has shown a very stable operation. From our observation of the theoretical and experimental results, we conclude that this dual-battery design has the potential to extend the average operation time of such a microcomputer by 200%. For a two-thirds utilization ratio in our design, we can gain four times the average operation time of a single-battery design from the theoretical results, and three and a half times the average operation time from experimental results. The difference between the theoretical results and the experimental results is a result of error in the battery-charging process. In addition, when our system operates in strong sunshine, it can work continually without battery exhaustion because the energy generation by the solar cells is greater than the energy consumption of 8051 system.【作 者】Y.-W. Bai; C.-L. Chang【刊 名】International Journal of Power & Energy Systems【出版日期】2002【卷 号】Vol.22【期 号】NO.3【页 码】125-135译文电池充电器集成电路的改进跟上移动手机功能快速增长的速度在全球无线连接的时代，几乎没有什么比让一个智能手机或移动互联网设备保持带电更重要了。便携式和手持设备功能的扩展性不断提高成为电池充电器集成电路设计者的一个重大挑战。高分辨率的屏幕和更大的储存能力并加上新的功能赋予电池，这就需要对电池充电器的技术要求，不仅要更有效率，同时要具有配电管理的能力。通过优化电源消耗来延长电池的寿命是掌上型电源管理的驱动力。但是当把手持的设备插入墙上，期望对他们进行充电时有有效地变化。最新一代采用高效率开关设计的充电器会代替传统的线性充电器。今天的客户仍旧需求更短的充电周期对其电池充电。相比传统的线性充电器，采用开关充电器的好处，除了效率高之外，还有一个很大的优点是通过电源提供能够促进充电电流。特别重要的是，当供电结束时USB接口处的电流可以实现被限制在小于500mA。更高的充电电流等于充电周期更短，这就满足了客户的期望。当今有两种被大多数手持设备使用的电池充电器-线性充电器和开关充电器。线性充电器有一段较长的历史。他们通常提供了相对高效，简单的方式对便携设备充电，同时产生噪音极小且不需要很多的外部元器件。但是，随着便携式设备变得更加复杂和添加新的功能层，他们就需要更大的电池容量。由于功能损耗，线性充电器呈现出不足，这很容易知道，假如用户想要对设备充电，且在同一时间又使用。同时使用设备和对其进行充电产生的热量会损坏系统或电池。这将会导致不好的结果。另一种选择是开关充电器，或者是开关模式电池充电器集成电路，它可以提供更高的电流水平，但却需要尽可能少的功率。历史上，这些类型的集成电路经常存在一些噪音的问题。此外，一些早期的几代开关模式的设备需要一些外部元件。朗读然而，开关模式的电池拓扑结构的好处是显而易见的。它们包括提高效率和降低功耗，以及快速的充电周期。这些器件也都能够由高的输入电压进行充电，这就可以允许使用较低成本无管制的适配器。他们可以从电流限制的能源中增加充电电流。来自开关充电器的噪音通常是在轻负荷运行时产生的，特别是在预处理时。随着噪声的减少，很多开关充电器进入了著名的脉冲跳跃操作。在脉冲跳跃时，脉宽调制的频率的变化是异步的。目前已开发出发达的电池充电器的集成电路使用一个开关式的充电器供应高的充电电流以最小的热量影响到系统使，然后在低电流充电模式下转换成为线性充电器，以减少噪音。这种脉宽调制开关模式充电器带有线性模式类型是一个很好的发展，提供了高效率的恒流（快速充电）的速度。开关式充电器通过脉宽调制开关调节器来控制很大的恒定的稳压电流充电（高达2A）。在电池预处理和锥形恒压充电模式将要结束时，它会自动转换到线性模式，从而降低了噪音，同时开关模式加速充电。一旦充电的电流水平低于300mA，则会完全的变成线性模式，由开关转换器产生的噪声就被消除。 但现在有进一步的发展。例如，一个新的手持设备的理想解决方案是单节锂/聚合物电池，它能提供高达1A的充电电流和先进的充电系统监控显示功能 USB兼100mA/500mA充电电流设置有利的是可编程的预充电和快速充电。许多产品还包括电池温度监测，以确保安全充电。如Intersil的公司是新一代充电器芯片开发的领头羊。这些所有的集成解决方案能够满足紧凑型应用，提供更高功率应用的充电控制器。现在的充电电压精度达到0.5个百分点，比起仅仅在几年之前，那时准确率为1个百分点就被认为是很好的的时候，这已经说明是有了进一步的发展。开关频率高达3 MHz，现在新的交换充电器提供高达2A的充电电流，如 ISL9220，这是1和2细胞的锂离子电池应用的理想选择。此外，新设计限制泄漏- 当没有附加输入功率时，现在典型的泄漏电流小于0.5 uA。在更小和更小的封装上这些改进也已成为可，如4 4毫米QFNs或2 x2毫米的CSPS，这在空间受限制的手机设备上节省了资源。 最新的电池充电器芯片还能够监视输入电压，电池电压，充电电流。当这三个参数中的任何一个超出特定的限制，该集成电路将关闭一个内置的N沟道MOSFET，以至于从充电系统移除电量给电池。这种灵活的效率的改进，就是现在这些重要的设备，这对持续增长和移动特征设置扩展，手持产品扩展是至关重要的。微型计算机8051系统太阳能电池供电与双充电电池之设计与建构单