精选优质文档-倾情为你奉上The design of the lithium battery chargerIntroductionLi-Ion rechargeable batteries are finding their way into many applications due to their size, weight and energy storage advantages.These batteries are already considered the preferred battery in portable computer applications, displacing NiMH and NiCad batteries, and cellular phones are quickly becoming the second major marketplace for Li-Ion. The reason is clear. Li-Ion batteries offer many advantages to the end consumer. In portable computers,Li-Ion battery packs offer longer run times over NiCad and NiMH packs for the same form factor and size, while reducing weight. The same advantages are true for cellular phones. A phone can be made smaller and lighter using Li-Ion batteries without sacrificing run time. As Li-Ion battery costs come down, even more applications will switch to this lighter and smaller technology. Market trends show a continual growth in all rechargeable battery types as consumers continue to demand the convenience of portability. Market data for 1997 shows that approximately 200 million cells of Li-Ion will be shipped, compared to 600 million cells of NiMH. However, it is important to note that three cells of NiMH are equivalent to one Li-Ion cell when packaged into a battery pack. Thus, the actual volume is very close to the same for both. 1997 also marked the first year Li-Ion was the battery type used in the majority of portable computers, displacing NiMH for the top spot. Data for the cellular market showed a shift to Li-Ion in the majority of phones sold in 1997 in Europe and Japan.Li-Ion batteries are an exciting battery technology that must be watched. To make sense of these new batteries, this design guide explains the fundamentals, the charging requirements and the circuits to meet these requirements.Along with more and more the emergence of the handheld electric appliances, to the high performance, baby size, weight need of the light battery charger also more Come more big.The battery is technical to progress to also request continuously to refresh the calculate way more complicatedly is fast with the realization, safety of refresh.Therefore need Want to carry on the more accurate supervision towards refreshing the process, to shorten to refresh time and attain the biggest battery capacity, and preventfrom the battery Bad.The AVR has already led the one step in the competition, is prove is perfect control chip of the next generation charger. The microprocessor of Atmel AVR is current and can provide Flash, EEPROM and 10 ADCses by single slice on the market Of 8 RISC microprocessors of the tallest effect.Because the saving machine of procedure is a Flash, therefore can need not elephant MASK ROM Similar, have a few software editions a few model numbers of stock.The Flash can carry on again to weave the distance before deliver goods, or in the PCB Stick after pack carry on weaving the distance through an ISP again, thus allow to carry on the software renewal in the last one minute.The EEPROM can used for conservancy mark certainly coefficient and the battery characteristic parameter, such as the conservancy refreshes record with the battery that raise the actual usage Capacity.10 A/ Ds conversion machine can provide the enough diagraph accuracy, making the capacity of the good empress even near to its biggest capacity. And other project for attaining this purpose, possible demand the ADC of the exterior, not only take up the space of PCB, but also raised the system Cost.The AVR is thus deluxe language but 8 microprocessors of the designs of unique needle object C currently.The AT90S4433 reference The design is with C to write, the elucidation carries on the software designs is what and simple with the deluxe language.Code of C this design is very Carry on adjust easily to suit current and future battery.But the ATtiny15 reference design then use edit collected materials the language to write of, with Acquire the biggest code density.An electric appliances of the modern consumption mainly uses as follows four kinds of batteries:1.Seal completely the sour battery of lead( SLA)2.The battery of NiCd3.The NiMHhydrogen battery( NiMH)4.Lithium battery( Li- Ion)At right choice battery and refresh the calculate way need to understand the background knowledge of these batteries. Seal completely the sour battery( SLA) of lead seals completely the sour battery of lead to mainly used for the more important situation of the cost ratio space and weights, such as the UPS and report to the police the backup battery of the system.The battery of SLA settles the electric voltage to carry on , assist limits to avoid with the electric current at refresh the process of early battery lead the heat.Want only the electricity .The pond unit electric voltage does not exceed the provision( the typical model is worth for the 2.2 Vs) of produce the company, the battery of SLA can refresh without limit.