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| 座谈主题：崭新的便携式设备充电技术 | ||
| 在线问答 | ||
| [问：alexan derlee] | 我有SONY F505V数码相机，使用1年，用的机会不太多，可突然一次充电过程中，提示已充满，装上后，显示电量不足，以后每次充电都是如此，我的笔记本现在也出现这种情况，电量始终在1%-3%之间，充不进，我想加大充电电流，将电池击活，请问可不可以？请问在锂电池充电过程中，有说第一次充电最少需要13个小时，有说充电4个小时足够了，请问哪一种说法正确？十分感谢！！！ | |
| [答：Xie_ Guo_liang] | My Sony NB PC had this problem too. Most likely your Li-ion battery has been dead. All the Li-ion battery should have protection circuitry inside. You a cannot use high current to charge the battery because it would protect itself.First time should charge the battery for > 12 hrs. | [2003-4-23 10:39:44] |
| [问：TI] | 在我的系统中有3。3V的GPRS模块、8位微处理器（也采用3。3v），大容量flash（32M），还有TI的5402DSP芯片、AD芯片和模拟放大电路以及LCD。其应用定位于便携式设备。请专家推荐一套电源解决方案。 | |
| [答：Wu_ Zhu_Xiang] | For the new cellular phone, several voltage are needed in the system. We have to need 3-4 LDOs to provide the system voltages, e.g. LP3985. Moreover, white LED for the LCD backlight need a driver, e.g. LM2703/04. For the further, Power management unit, PMU, will be use. It consists of those building block, e.g. LP3938. You can contact our sale office to get more information. | [2003-4-23 10:41:42] |
| [问：Anoymous] | 现在很多手机采用锂离子聚合物电池，它的充放电特性和一般的锂电池有何不同，在充电器的芯片上是否也有不同？ | |
| [答：Xie_ Guo_liang] | Li-polymer electrial characteristics is similar to Li-ion. The charge and discharge characteristics are also similar. Therefore, charger should be the same. | [2003-4-23 10:42:06] |
| [问： Anoymous] | 作为便携式设备的充电设备，其体积、质量的发展趋势也必将随之变小，不知专家对：1、“便携式设备的充电设备与便携设备的一体化的发展趋势做怎样的预测？”2、“未来会不会出现，与ATM提款机类似的，在街头出现的能够为多种设备充电的公共充电装置！”谢谢专家的解答！各位专家辛苦啦！ | |
| [答：Wu_ Zhu_Xiang] | 1. The new power management unit, PMU e.g. LP3938, will integrate the charger circuit and the power management circuit together. So, the charger will already in every portable product. | [2003-4-23 10:44:42] |
| [问：yakyao] | 您好：我主要从事DC-DC的研发工作，我想问的问题是便携式充电一般采用哪些电源拓扑结构？所谓电源拓扑结构是这样的：如CPU电源采用降压型，LED电源采用升压型等。另外便携式充电电源拓扑的小信号模型及大信号模型是怎么样子的？谢谢 | |
| [答：Xie_ Guo_liang] | Usually the charger have a AC-DC adapter (linear or switching). Then the charger use step down DC-DC conversion with constant current and constant voltage control. Constant current is done by current sense resistor and feedback to the control loop of the DC-DC to set charge current just like current protection in a normal DC-DC converter. | [2003-4-23 10:45:05] |
| [问： yinhuilong] | 在网上我没有找到相关电路的资料，如lp3946。是何种类型的？最大充电电流为多少？另外我需要知道，有无其它电池形式的充电模块（性价比好的）？谢谢！ | |
| [答：Xie_ Guo_liang] | LP3946/5 will be available in middle of this year. It is a preset/programmable CC/CV charger with different charge current/ voltage settings. Other charger IC from NS are LM3420/3620/3621/3622,etc. You can visit our website at power.national.com for the datasheet and information | [2003-4-23 10:48:16] |
| [问：cheng chengvs@ 163.com] | 这种便携式设备充电能持续多长时间呢？而且它的发热温度高吗？ | |
| [答：Xie_ Guo_liang] | LP3945/6 has a built-in power transistor. Max. input voltage is 6V and charge current is 1A. The package is LLP which use PCB trace to dissipate the heat. If the PCB area is large enough there should be no heat problem. | [2003-4-23 10:50:39] |
| [问：hong01 @263.net] | 我公司从事PDA-GPS-GSM的系统集成工作。急需解决用两节镍氢可充电电池对手持设备供电的电路指标如下：电源电压：1.8-2.6V；输出电压：3.3V；输出电流：800mA；电源纹波：<50mV。这个电路最好既可当供电路用，又可当充电路用。 | |
| [答：Wu_ Zhu_Xiang] | Usually, the charger circuit and the power supply is an independ circuit. I suggest to use LP3945/46 for the charger. A boost converter is used to step up the 1.8-2.6V to 3.3V@ 800mA. National Semiconductor have many DC/DC converters. You can contact our Sales office or visit our web site: Power.national.com | [2003-4-23 10:53:15] |
| [问：Anoymous] | 您的产品与市场上的同类成熟产品相比，能为便携式设备设计生产商提供哪些更为优越的性能，提高产品的市场竞争力？谢谢。 | |
| [答：Wu_ Zhu_Xiang] | There are several advantages for our products:1. Provide Chip Sale Package2. Highly integration: Most the necessary power management circuit is integrated in our PMU. Those can help the user to reduce the overall size with higher performance. | [2003-4-23 11:00:00] |
| [问：wangjmin @21cn.com] | 请问D/A转换后输出达不到要求可能有哪些原因？ | |
| [答：Xie_ Guo_liang] | It may be due to the orignal noise is too big which may be due to op-amp is not good enough. | [2003-4-23 11:03:41] |
| [问：zhao junhui] | 锂电池充电方式与铅酸电池的相似,该芯片可否用于ups电源充电系统中 | |
| [答：Xie_ Guo_liang] | Li-ion and Lead acid battery have different electrical characteristics. The charge and discharge characteristics are also different. Lead acid can discharge at a much higher instantanous current while Li-ion cannot. UPS requires high instantanous current for the SMPS requirement. | [2003-4-23 11:06:04] |
| [问：echi] | 怎么能较精确的检测到电池的容量？通过检测电池开路电压来判断其容量精确度有多高？ | |
| [答：Wu_ Zhu_Xiang] | The circuit will be very complex for detecting the capacity accuracy. The accuracy for detecting the voltage of the battery is not very high in normal. Since the voltage of Lion battery will drop rapidly at the end of life. So, it is accuracy for this application. | [2003-4-23 11:06:27] |
| [问：qli2003] | 1、能否提供7.6V锂离子电池充电器解决方案；2、标称电压为7.6V锂离子电池的过压电压点和过放点是多少。谢谢各位专家 | |
| [答：Xie_ Guo_liang] | NS currently have LM3420/3620 solution. Pls visit power.national.com for datasheet and details.The charge termination voltage (max.) for a 7.6V Li-ion battery is 8.2V or 8.4V (depends on Coke or Graphite anode). Different users may set different min. discharge voltage. Usually it is around 5.5V to 6V. | [2003-4-23 11:09:45] |
| [问： wenli-gao] | 1、简单可靠的锂电池（2节）充电技术，有现成的设计方案或产品2、有没有廉价的锂电池电源充放电管理方案3、我现在急需锂电池（2节）应用于便携设备中，能否给出一个满足上述要求的实用的电路设计？谢谢 | |
| [答：Wu_ Zhu_Xiang] | We have several products for rechargable Lion battery. LM3620 is one of the cost effective part for 2 cell Lion battery. Pls contact our sale office or visit our website: Power.national.com, to get further information. | [2003-4-23 11:09:51] |
| [问：znh1979] | 有一个这样的问题：当冲多节电池时，会有不均衡的情况，请问你们怎样解决！ | |
| [答：Xie_ Guo_liang] | For Ni-Cd or NiMH you will need to use equalization circuitry to balance the charge rate at different cells. For Li-ion battery, it has built-in protection circuitry for each cell which would do the equalization as well. | [2003-4-23 11:11:40] |
| [问：tsm998] | 在锂离子电池的充电设备中，能否增加对电池好坏的自动检测功能？这样我们在购买手机电池的时候就可以快速的判断出电池的好坏，谢谢！ | |
| [答：Wu_ Zhu_Xiang] | It is difficuilt to add this function into the system since there are many factors for the defected battery. Moreover, it will ibcrease the system cost. | [2003-4-23 11:12:52] |
| [问：rocky_jing] | 鋰電池充電方法為恆定直流,還是采用脈沖方式?電壓如何控制?qing | |
| [答：Xie_ Guo_liang] | Usually it is CC/CV method. This is most safe method and has a higher charge cycles. Some user may use pulse charge method for quicker charge. For example, if the termination voltage is 8.4V you can use 8.8V and 8.4V pulse with 50% duty cycle for quicker charge. | [2003-4-23 11:14:36] |
| [问：张皖] | 怎样进行11.1/3600mAH锂电池简单高效充电 | |
| [答：Wu_ Zhu_Xiang] | Usually, a constant current and constant voltage charging method is used for the Lion battery. LM3402 can be used to charge 3 cell Lion battery. There are several charger circuit in our datasheet. You can download it from our website: Power.national.com | [2003-4-23 11:16:16] |
| [问：dsp3680 @sohu.com] | 1。我希望在－43～70摄氏度的范围内使用充电电池，锂电池能胜任吗？通过查资料我发现锂电池的低温特性很差，不知能否使用锂电池。2。我希望能用快速充电器在1～2小时内即将3000mAh以上的电池充满，难度是否很大？ | |
| [答：Xie_ Guo_liang] | Usually Li-ion should be charged between 0C to 50C. You need to consult the Li-ion battery manufacturer for higher temperature charging. This may be done by lowering the charging current.It is possible to charge a 300mAH Li-ion battery in 2hrs. You will need high charge current (>3A) which require switching mode instead of linear mode charger. | [2003-4-23 11:17:40] |
| [问：yin huilong] | 现在推出的充电模块与原有的LM3622有什么区别？有哪些优点？ | |
| [答：Wu_ Zhu_Xiang] | The major advantages and difference are:-the pass or power transistor is integrated-Programmable Charge Current from 500mA to 950mA-Charge status indicators-buit-in 5.6hour timer | [2003-4-23 11:22:40] |
| [问：包学俊] | 唤醒，保持，涓流各时间请详细图表说明！！？ | |
| [答：Xie_ Guo_liang] | first one is wake up charge. When battery is over discharged it cannot be charged with highe current or it is damaged. It need a very small charge current to charge the battery to certain voltage then a high charge current for normal charge.second one is maintenance. When the battery is fully charged the charger stops charge. The battery will self discharge slowly over time. The charger should be able to keep the battery fully charged even the battery is in the charger for one year.Pls explain more on the third one. | [2003-4-23 11:24:59] |
| [问：fansr] | 如何简单准确的测定充电时间 | |
| [答：Wu_ Zhu_Xiang] | The battery voltage of the Lion battery is used for detecing the end of charge. | [2003-4-23 11:25:28] |
| [问：ecnan jing_EBY7E] | LP3946的充电时间设定为5。6小时为什么手机在使用一段时间后充电半小时便显示充电完成？ | |
| [答：Xie_ Guo_liang] | The 5-6hours timer is just for safety consideration. The charge should be completed within 1-2hrs. In case the charger do not work properly the charger will stop charging in 5-6 hrs to prevent from damaging the battery or fire hazard | [2003-4-23 11:27:39] |
| [问：ljmxqf] | 怎样判定 WAKE UP 已完成 | |
| [答：Wu_ Zhu_Xiang] | It depend on the battery voltage, e.g. for 1 cell Lion battery, 3.3V will be its threshold voltage. This voltage will also depend on the battery manufacturer. Pls check with your battery vendor. | [2003-4-23 11:31:23] |
| [问：yin huilong] | 对与终止电压为4.2V的电池，选多少终止电压为最佳？是正好4.2V还是比它小一点。电压误差多少？ | |
| [答：Xie_ Guo_liang] | termination voltage should be set at 4.2V in this case. The tolerence should be < 1%. Over voltage will damage the battery which result in lesser charge cycle (e.g. 500 down to 300 cycles). Under voltage will result in less battery capacity For example, using 4.1V to charge may result in >20% less battery capacity. | [2003-4-23 11:32:04] |
| [问：frankie _zhang] | 如果用單片机檢測過壓是檢測峰峰值還是平均值﹖一般采用何种方法較好﹖ | |
| [答：Wu_ Zhu_Xiang] | Usually, it detect the peak, not average. Peak detection is more cost effective and safe. The ciruir will be complex to detect the average vaule. | [2003-4-23 11:34:28] |
| [问：TOM_GUO] | 请问，为什么说用脉冲电流充电25秒后，电池的电压还没达到3V的话，电池就是损坏的呢？谢谢！ | |
| [答：Xie_ Guo_liang] | From our experience, using high pulse current (the charge current need to be adjusted for different rated capacity battery) for the wake up charge cycle should reach 3V within 25S. If not the battery most likely is damaged. | [2003-4-23 11:34:43] |
| [问：shawdg @online.sh.cn] | 现在许多便携式电脑的锂电池在使用一段时间后，充电时间很短即显示充满，但使用时电量不足，是何机理？能否修复？ | |
| [答：Wu_ Zhu_Xiang] | This issue is due to the aging of the battery. It cannot be recovered. | [2003-4-23 11:35:38] |
| [问：dahaha] | 便携式设备充电技术受环境的影响大吗？比如在东北冬天低温条件下 | |
| [答：Xie_ Guo_liang] | The environment temperature affects the battery charging very much. Normally Li-ion battery should be charged within 0C-50C. Outside this temperature the charge (discharge) current need to limited which need to consult battery manufacturer. | [2003-4-23 11:36:41] |
| [问：sammy cheung] | 0充电记录的锂电池在第一次充电的时候应采用何种方式？ | |
| [答：Xie_ Guo_liang] | It can be used CC/CV method and usually should be put in the charger for more than 12 hrs. | [2003-4-23 11:38:38] |
| [问：niexu zhong] | 电池是一个化学器件，不同公司的产品特性又比较大的差异，是否会对充电产品的设计产生较大的影响 | |
| [答：Wu_ Zhu_Xiang] | Yes. | [2003-4-23 11:40:02] |
| [问：zhou ximing] | 温度检测的是环境温度还是电池体的温度？ | |
| [答：Xie_ Guo_liang] | Both battery and environment temperature need to be detected for safe fast charge. | [2003-4-23 11:40:33] |
| [问：zhou ximing] | 假如一电池的循环寿命是500次，如果在电池还有60%甚至是90%电量就进行充电，是否会影响电池的循环寿命？或者已经算是500次里面的1次？ | |
| [答：Xie_ Guo_liang] | Li-ion do not have memory effect so it can be charged when battery is not fully discharged. | [2003-4-23 11:42:20] |
| [问： TOM_GUO] | 请问，锂离子电池充电和铅酸电池充电有什么不同之处？NS有针对铅酸电池充电的方案吗？谢谢！ | |
| [答：Wu_ Zhu_Xiang] | We don"t have product for Lead Acid battrey. They need a difference circuit. | [2003-4-23 11:42:59] |
| [问：yin huilong] | 本身充电模块的终止电压为4.2V，如何能过量充电？ | |
| [答：Wu_ Zhu_Xiang] | At the end of charge, you can still use a constant volatge mode to charge the battery. | [2003-4-23 11:45:04] |
| [问：ljp] | 外接开关器件，FET与双极晶体管哪个更好些？ | |
| [答：Xie_ Guo_liang] | For linear mode charger it does not make big difference. For switching mode charger normally mosfet have higher efficiency than biplor transistor. | [2003-4-23 11:45:09] |
| [问：大兔子] | 有一点不太明白：为何终止充电的电压误差越大，电池的容量越小？这种容量的减少是永久的还是临时的？ | |
| [答：Wu_ Zhu_Xiang] | It is because the battery may not fully charged. So, you will find that the capacity is less. | [2003-4-23 11:48:23] |
| [问：reidgjiao] | 充电的检测主要有几种方法?其电流是如何调节的?保护电路的主要目的是什么? | |
| [答：Xie_ Guo_liang] | termination detection method includes temperature (max. and delta), and voltage (max. and point of change).charge current is adjusted by the current detection loop in the charger circuitry.protection circuitry is to protect battery from over charge which may cause fire hazard and even explosion. | [2003-4-23 11:49:49] |
| [问：ecnan jing_EBY7E] | 随着锂电池的容量增大，由于锂电池的自身优点将用于动力请问NS有无相应的充电管理芯片？ | |
| [答：Wu_ Zhu_Xiang] | Currently, we are focus on the portable applications. | [2003-4-23 11:53:11] |
| [问：frank@upp ertech.com.cn] | 您好！请问可充锂电的充电时间与它的容量是否有一个大概的标准。充电时间长会增加它的初期电量，每次都会这样吗？ | |
| [答：Xie_ Guo_liang] | The charger should match with the battery (high capacity rated battery should be charged with a high current charger)The charge time should not affect the initial battery capacity as long as the battery is fully charged (some chargers may take longer time and some shorter time but should affect the initial capacity) | [2003-4-23 11:54:23] |
| [问：ecnan jing_EBY7E] | 由于LM36XX，LP39XX的充电电压为4。1伏，而有的电池标称电压为3。6伏这样经常过冲对电池有无影响？ | |
| [答：Xie_ Guo_liang] | For Li-ion battery nominal battery voltage is 3.6V but the charge voltage should be 4.1V (or 4.2V). This is normal. | [2003-4-23 11:56:13] |
| [问：pengy] | 专家好，请问锂电池放电时间是否是其额定安时数除以放电电流，如果电流比较大，其放电时间会不会象铅酸电池那样特别短？谢谢。 | |
| [答：Wu_ Zhu_Xiang] | Yes. When the dischage current is higher, the discharge time will be less. | [2003-4-23 11:56:14] |
| [问：gracecheng @online.sh.cn] | 看了谢先生的讲解后,获益良多.非常感谢您给予的讲解. 可否再请教一下,对于便携式产品的电池,应如何进行电路保护? 盼复.谢谢. | |
| [答：Xie_ Guo_liang] | There are two protection circuits. One is for battery cells. One is for charger. For battery cells there are several IC makers provide this part. For charger, it should have over temperature, current and voltage protection. | [2003-4-23 11:59:14] |
| [问：guojiyan@ datang mobile.com] | 请问你所说的通过USB口充电如何实现？ 多谢。 | |
| [答：Wu_ Zhu_Xiang] | There is 5V supply voltae in the USB. The USB charger will use it as it as supply voltage. the other circuit will be similar to the normal one. | [2003-4-23 11:59:47] |
| [问：qin] | 恒压/恒流充电叫醒模式有多长？是否越短越好？ | |
| [答：Xie_ uo_liang] | There is no specific time limt for wake up charge mode. For LP3938 we use high current pulse wake up charge to shorten the wake up time within 25S because we want to make sure the users know if the battery is defective. If it takes too long the users may not know. | [2003-4-23 12:01:18] |
| [问：rocky_jing] | 鋰電池充電方法為恆定直流,還是采用脈沖方式?電壓如何控制? | |
| [答：Wu_ Zhu_Xiang] | It is constant current and constant voltage charger. The voltage is setted according to the battery. | [2003-4-23 12:02:12] |
| [问： 61angel] | 请问这里电压误差和充饱程度比值那部分当中误差是指负误差还是正误差？ | |
| [答：Xie_ Guo_liang] | Both +ve and -ve error affects the performance. -ve error cannot fully charge the battery. +ve error will damage the battery and decrease the charge cycles. | [2003-4-23 12:02:28] |
| 非在线问答 | ||
| [问：] | 1.lp3946最大能对多大容量的电池进行充电。 2.该器件的销售价格为多少？ | |
| [答：] | 1. LP3946 will stop charging and jump to charge complete mode when the battery reaches its end-of-charge stage which is indicated by the battery voltage. In other words, it is independent of battery's capacity.2.Pls contact our Sales office for further information. | |
| [问：] | 1.锂离子电池为什么没有对其尺寸及规格进行统一,如AAA,AA等. 2.可否介绍一下有关Ni-MH电池的特性及充电控制方法. | |
| [答：] | 1. It is because different battery manufacturers have their own standard. 2. The charger behavior for Li-ion and Ni-MH is different. The charge curves of Ni-MH will appear slightly flat due to the differences in chemistry. Constant current and constant voltage is used to charge Ni-MH but both battery voltage and temperature have to monitor for changing the charging stage. | |
| [问：] | 1.如何减少充电过程中的发热? 2.通常情况下,当充电器接在220VAC上,但另一端并不接设备时,充电器仍微微发热,如何做到此时不发热? | |
| [答：] | 1. Using efficiency power supply, e.g. switching power supply is beteer than linear one. 2. Turn-off all the devices to minimize the quiescent current.The transformer for the linear power supply will generate heat. Switching one can reduce it. | |
| [问：] | lm2733 为什么有两种频率，怎么选择？SW 端输出的是不是这个频率？ | |
| [答：] | Different switching frequency is for different application or requirement. The advantage of higher switching frequency is smaller inductor size, i.e.to reduce the overall system size. However, some application will have EMI concern. So, there are 2 switching frequency for the customer to choose. You can find the switching waveform at SW pin. Its frequency is same as the device's switching frequency. | |
| [问：] | LM36XX系列有无过热保护？ | |
| [答：] | The LM36xx is a charge controller for Lithium-Ion batteries. This monolithic integrated circuit accurately controls an external pass transistor for precision Lithium-Ion battery charging.So, it will not have thermal issue. No thermal protection is built in the device. | |
| [问：] | LP3946、LP3945 及 LP3938等芯片的具体应用是什么？ 恒压、恒流源充电器的特点有哪些？都有各自的什么优势？它们的规范是什么？ 锂电的充电方法有哪些？具体过程怎样？有什么特性？ | |
| [答：] | LP3945/46 is battrey charge management IC. LP3938 is power management IC for cellular phone with charger circuit.Constant current and constant voltage charging method is used for Li-ion battery. Constant current mode will be used to charge the battery very quickly. Then, it change to constant voltage mode near the end of charge.It is low cost and reliable solution. | |
| [问：] | LP3946充电过程中，当第一次充满以后，若电池未取出会有电流泄漏，这样会产生2次充电，使电池的电压大于4.1V，这样会造成对电池的多次往复充电，会不会对电池寿命造成损耗！ | |
| [答：] | LP3946 will monitor the battery voltage. If it is greater than 4.1V, it will use a constant voltage mode to charge the battery. | |
| [问：] | LP3946的价格大概是多少，中国大陆能买到吗？ | |
| [答：] | Pls contact our Sales office for further information. | |
| [问：] | lp3946是否可用于充镉镍和镍氢电池？ | |
| [答：] | It can use for Ni-MH and Li-ion battery. | |
| [问：] | NS公司是否有类似电池均衡器的产品（equalizer） | |
| [答：] | We don't have this type of product. | |
| [问：] | NS有针对锂离子电池及聚合物电池充放电的方案吗？ | |
| [答：] | Yes. Pls contact our Sales office for further information. | |
| [问：] | usb充电采用恒功率充电，充电的原理能谈一下吗？ | |
| [答：] | It will be same as the normal battery charger. The only difference is the supply voltage is from USB port. | |
| [问：] | what is the speciality of your chip? | |
| [答：] | The pass transistor is integrated. The package is small chip scale package, LLP-14. 5.6hr Timer is built in… | |
| [问：] | why can"t find LP3946 datasheet on NS Website now? | |
| [答：] | It is still in preliminary stage. Engineering sample and demo board is available now. | |
| [问：] | 便携式设备充电技术国内外的市场行情与展望？ | |
| [答：] | More and more portable consumer products is coming now, e.g. PDA, cellular phone, MP3 player, digital camera and etc. Those product need battery charger. So, this market will become important and the total revenue will continue to increase. | |
| [问：] | 便携式设备充电技术需要注意什么问题? | |
| [答：] | In general,the reliability, safty and heat dissipation of the battery charger should be taken care. | |
| [问：] | 便携式设备充电技术在未来几年内会有什么发展? | |
| [答：] | New technology, e.g. new battery technologies fuel cell and adaptive chargers, will be developed and commercialized. | |
| [问：] | 充电的检测主要有几种方法?其电流是如何调节的?保护电路的主要目的是什么? | |
| [答：] | In general, the battery voltage, temperature and charge current have to be monitored. The charge current is set by the circuit for the constant current mode. During the constant voltage mode, it is automatic cahnged since the the input impedence of the battery change. The protection circuit should be inside the Li-ion battery pack. It is to protect Li-ion battery for improper handle, e.g. short circuit. | |
| [问：] | 充电电流可以选择吗？最大充电电流？ | |
| [答：] | rogrammable charge current from 500mA to 950mA. | |
| [问：] | 充电管理电路的温升如何？ | |
| [答：] | For the charger circuit, the heat dissipation should not be a big issue provided that the charge current is not large. | |
| [问：] | 充电过程中经常会出现那些充电异常情况？ | |
| [答：] | The abnormal issues usually are due to the battery or bad contact. Those will cause partial charge or malfunction. | |
| [问：] | 充电设备的使用寿命如何判断 | |
| [答：] | You can use the mean time between failure, MTBF, to estimate the life time. | |
| [问：] | 充电完成后，电子开关的漏电流有多大？ | |
| [答：] | It would be close to zero. Actually, it will depend on the device. | |
| [问：] | 第一次必须充12小时以上的原因是什么? | |
| [答：] | It is to make sure the battery is fully charged. | |
| [问：] | 电池没有用完（比方说用了一半）就开始充电，这样算不算增加了一个充电周期？ | |
| [答：] | Yes, it is a new cycle. | |
| [问：] | 电压，电流检测精度能达到那个数量级？ | |
| [答：] | 1% for battery voltage, around 10% for the charge current. | |
| [问：] | 电源的体积如果变小，那怎么去解决发热问题？ | |
| [答：] | An efficiency circuit is used to reduce the heat dissipation, e.g. the efficiency of switching power supply can be above 80% but linear one is around 50%. | |
| [问：] | 電池充電是采用脈沖充電還是直流? | |
| [答：] | Both constant curent and pulsed constant current can be used. | |
| [问：] | 对于不同电压值的电池，用同一充电控制电路可以吗？ | |
| [答：] | It is possible.If the device don't have auto-detection, manual jumper setting is needed. | |
| [问：] | 关于你们的充电芯片，是否有技术手册？可否提供？ | |
| [答：] | Pls contact our Sales office for further information. | |
| [问：] | 过充电对电池的寿命是有影响的，如何避免？谢谢！ | |
| [答：] | The charger circuit should avoide the overcharge the battery via battery voltage and temperature monitoring. | |
| [问：] | 恒压和恒流充电各自有何优缺点？ | |
| [答：] | A constant current mode is used at the beginning since the input impedence of the battery is low at that time. If a constant voltage mode is used, a huge current will flow into the battery. It will generate a lot of problem and damage the circuit and battery.After the battery voltage reach a certain level, a constant voltage mode is used to charge the batttery. At that time the charge current will be lower and will not damage the battery. | |
| [问：] | 恒压和恒流充电模式如何确定？是否自动转换？ | |
| [答：] | It depend on the battery voltage. The charger should be auto-detect it and change the charge mode. | |
| [问：] | 今天介绍的芯片都有何种封装形式? | |
| [答：] | It is a chip scale package, called Leadless leadframe Package LLP. | |
| [问：] | 聚合物电池可靠度信赖测试的项目、条件及判定基准是什么？能从什么地方查询这些资料？谢谢！ | |
| [答：] | Pls check with the battery manuafacturer for detailed information. | |
| [问：] | 看到广告上说此充电技术是为锂离子电池而开发的，我们常使用的手机锂电池也能使用该技术吗？ | |
| [答：] | One of this target applications is to charge Li-ion battery for mobile phone. | |
| [问：] | 可实现 不同电压水平的 同级别快速充电吗？ | |
| [答：] | It is possible.If the device don't have auto-detection, manual jumper setting is needed. | |
| [问：] | 快速充电对电池寿命有无影响？充电电流多大可算为快速充电？ | |
| [答：] | In certain conditions, the fast charge will not affect the battery life. We should use the charge time to say whether it is fast charge or not.Usually, 1C charge current can be considered as fast charge. | |
| [问：] | 锂电池额定容量判定是满充状态下1C放电时间不小于1小时吗？谢谢 | |
| [答：] | Capacity is the amount of electric charge that a battery can hold. It is usually expressed in mAh(milliampere hour), I.e. Capacity= Electric Current X Hour. For example, a battery with a capacity of 1500mAh can pass an electric current of 1500mA(1.5A) for 1 hour. | |
| [问：] | 锂电池与聚合物电池最大的区别是什么？它们各自的优点是什么？哪一种比较环保？谢谢 | |
| [答：] | The major differences is the energy density and the flexiblity.Li-ploymer will have higher enery density and can be formed as different sharp. Li-ion will be more cost effective. | |
| [问：] | 锂电池在充放电过程中有没有可能发生爆炸或漏液,我曾遇到过手机电池充胀了的情况.请问这是如何发生的?如何避免? | |
| [答：] | It will depend on the discharge conditions.Li-ion battery will be very dangerous if we cannot handle it properly. So, usually, there are a protection circuit inside the battery. Pls contact the corresponding battery manufacturer for the battery failure. | |
| [问：] | 锂聚电池是否是任意形状？ | |
| [答：] | Yes. | |
| [问：] | 锂离子电池的充电方法-用完后再充电与用一半(或一段时间)再充电，哪一种方法更好？ | |
| [答：] | Both cases is fine for Li-ion because it don't have memory effect. We recommend to charge it after it fully discharge. | |
| [问：] | 锂离子电池的充电要注意什么问题？和一般电池如锰氢电池充电有何不同？ | |
| [答：] | The charging algorithm is different to different type battery. The charging method for Li-ion battery is simple compared with the other type battery. The battery voltage and current have to be monitored. | |
| [问：] | 锂离子电池如果不能正常充电会导致什么结果？ | |
| [答：] | The worst case is that it will explode. | |
| [问：] | 锂离子电池之所以未能迅速取代镍镉/镍氢电池，除了成本问题外，还有哪些因素影响？ | |
| [答：] | Cost is the major issue. The other factor is the manufacturing capacity. | |
| [问：] | 脉冲电流充电时的脉冲频率和脉冲宽度对充电效果有何影响？ | |
| [答：] | It will affect the charge time. | |
| [问：] | 没有检测ID电阻功能的座充能安全使用吗？谢谢 | |
| [答：] | It is not recommended to use. | |
| [问：] | 目前市场上便携式设备很多,在我们到现场进行设备调试时经常要携带不同的充电器,很不方便.目前在便携式设备方面有没有统一的充电技术规范,是否可以作到一机多用?谢谢! | |
| [答：] | In the market, there is an intelligent charger for several different tpye battery. | |
| [问：] | 那么主要的充电的功能如何,对那些设备效果最好,请举例~ | |
| [答：] | The major advantages is: a. the pass transistor is intergated. b. The package is small chip scale package.c. all the necessary chargering circuit is integrated into a single chip.The target application are : cellular phone, PDA, digital camera and all portable product which require rechargable battery. | |
| [问：] | 能解决电池充电时发热的问题吗 | |
| [答：] | The battery will generate heat when it is charged. It is a chemical effect. | |
| [问：] | 你好，我想请教的问题是在设计大功率电源与小功率电源考虑的侧重点有哪些不同。作为一个专业的电源公司是因该向方案应用方面发展还是更强调完整的设计 | |
| [答：] | In general, the power supply with higher output power should have tighter specification and more reliable. For small power supply, the cost will be a critical factor since there are many supplier in the market. For a small and professional company, they should focus on a certain market and work with the customer closely or as a consultant. | |
| [问：] | 你好：在多节电池充电过程中，如何对每节电池进行保护？有相应的芯片吗 | |
| [答：] | The protection circuit is for the whole battery, not for each cell. | |
| [问：] | 您好，请问所有的锂离子电池都可以充电吗？可以充电的和不能充电的主要区别是什么？ | |
| [答：] | Not all Li-ion battery is rechargable. The major difference is chargable or not. | |
| [问：] | 您好： 充电方式有恒压、恒流和脉冲，请问哪一种对电池更有利些；我现在正用单片机设计多路充电器，那么AD采样应在什么时候测量（是加电的时候？还是撤电的时候？）。 | |
| [答：] | The advantages of pulsed charger is high efficiency and shorter charge time. AD sampling should be done during charging. | |
| [问：] | 您觉得将供电电路与充电电路集成到一个芯片中会有意义吗？ | |
| [答：] | It will depend on the application. For example, it will not be suitable for portable product since the bulky size of the power supply. | |
| [问：] | 请提供该充电器的电原理图和性能指标 | |
| [答：] | Pls contact our Sales office for detailed information. | |
| [问：] | 请问，能否用三节电池的电能对一节3.6V/600mA.h的可充电电池进行充电？ 平时工作时用三节电池工作，当三节电池电量不足时，用备用3.6V电池工作，更换三节电池后，三节电池的电能对3.6V电池充电，充电电路如何设计？ | |
| [答：] | 3 cell battery can charge 1 cell battery. Pls aware that the battery voltage if different. So, there is a DC/DC converter for the single cell battery to make sure that the system have proper supply voltage.The charging circuit is similar to the normal one. | |
| [问：] | 请问：1.该项技术是否为专利技术？ 2.主要的优势在那里？是否有技术参数及说明？ | |
| [答：] | The major advantages is: a. the pass transistor is intergated. b. The package is small chip scale package.c. all the necessary chargering circuit is integrated into a single chip. | |
| [问：] | 请问：便携设备待机时，其中的镍镉电池是长时间充电还是采用电路关断处理？ | |
| [答：] | When the system is in the standby time and connected to the ac adapter, the battery will be in charging mode and disconnect to the system. | |
| [问：] | 请问：锂离子电池充电与铅酸电池有什么差别，NS有对铅酸电池充电管理的方案吗 | |
| [答：] | The major difference is the energy density, battery voltage and charging characteristic. | |
| [问：] | 请问：这种技术的优优越性是什么？ | |
| [答：] | System solution is smaller and more cost effective. | |
| [问：] | 请问LP3945的自耗电流有多大?能否用于便携式手动发电充电器?谢谢! | |
| [答：] | LP3945 is a CMOS device. Its quiescent current is in uA. One of the major target application is cellular phone. | |
| [问：] | 请问LP3946的价格。请把详细的资料邮给我。谢谢。 | |
| [答：] | Pls contact our Sales office for further information. | |
| [问：] | 请问LP3946芯片的封装类型、充满后静态功耗如何？另外，可否先给个参考报价？ | |
| [答：] | It is in chip scale package (14pin LLP). Pls contact our sales office for further information. | |
| [问：] | 请问便携式充电设备的使用寿命一般是多少？ | |
| [答：] | It will depend on the design and the components' quality. Usually, it will be over 5 years. | |
| [问：] | 请问充电时如何测量电池的容量? | |
| [答：] | You can estimate the capacity by calculating the charging current times the charging time. | |
| [问：] | 请问贵公司有没有这样的模块： 由5V电源电压直接得到3.3V@1000mA 要求体积尽可能小， 另外散热情况如何，是否另需散热设备？谢谢！ | |
| [答：] | We don't have power module but we have a DC/DC converter chip, Simple Switcher LM2675M-3.3. | |
| [问：] | 请问锂电池充电器可以给镍氢电池充电吗？充电一般需要充电器的输出略高于电池的电压，那么4.2v输出的充电器可以充1.2的电池吗？ | |
| [答：] | Li-ion battery chager cannot charge NiCd battery. For safty and reliablility reasons, different type battery need to use their corresponding battery charger. | |
| [问：] | 请问你们的便携式设备充电技术跟传统意义上的充电技术有哪些优势和劣势? | |
| [答：] | The major advantage is that it integrate all the necessary charge ciruit into a siingle chip. | |
| [问：] | 请问如何通过软件实时监控充电电压和电流? | |
| [答：] | You can use a A/D converter to convert the analog signal, i.e. battery voltage and charge current, to digital signal. Then you can use I2C interface to send the data to MCU and monitor by the software in MCU. | |
| [问：] | 请问它用在哪些方面效果最佳呢？ | |
| [答：] | The target application is cellular phone, PDA, digital camera and all portable products which use single cell LI-ion and Ni-MH. | |
| [问：] | 请问在手机锂电充电器上，NS有最新方案出台吗？ | |
| [答：] | LP3945/46 and LP3938 is new solution for battery charger of cellular phone. | |
| [问：] | 请问怎样冲电才能延长电池的使用寿命和待机时间?我的笔记本电脑电池原来可以用近3小时,现在只能用1小时. | |
| [答：] | Today, most of the battery for Notebook PC is Li-ion. It will not have memory effect. So, no special procedure for the charging the battery. However, the battery capacity will be decreased due to the aging issue of the battery. The user will be recommended to take off the battery when they are using the AC adapter in order to extend the battery life. | |
| [问：] | 请问这里电压误差是指负误差还是正误差？ | |
| [答：] | It is positive and negative. | |
| [问：] | 请问这种设备对过充电有哪几种控制方法。谢谢！ | |
| [答：] | It will monitor the battery voltage and charge current. | |
| [问：] | 如采用单片機編程充電控制,輸出波形是怎樣的? | |
| [答：] | It will depen on your sesign. It can be linear or pulsed. | |
| [问：] | 如果电池冲完电后的电压高于所要电压,会产生怎样问题. | |
| [答：] | Usually, the battery voltage have a range. For example, Li-ions battery will be 2.7V to 4.1V. The portable system will consider the max. battery voltage as 4.1 to 5V. So, a little bit higher battery voltage will not affect the system operation. | |
| [问：] | 如何处理充电前电池中所留有的一部分电量？它对电池的寿命有何影响？ | |
| [答：] | In general, the rechargable battery will have memory effect. So, it is required to discharge fully before charging. Otherwise, the battery's capacity will be decreased. | |
| [问：] | 如何理解过量充电会增加初期的储电量和终止电压误差越大（过充）电池储电量便越少？谢谢！ | |
| [答：] | It will be battery chemistry related issue. Pls contact the correponding battery manufacturer. | |
| [问：] | 如何实现电池的并联充电 如何实现多组电池组的同时充电 如何解决单节电池（Ni-Cd or Ni_MH)充电监控的灵敏度问题 | |
| [答：] | There are a lot of technical issues, circuit design and the components selection involved. Pls contact our sales office for further information and discussion. | |
| [问：] | 如何有效的可以选择的控制充电电流，增长电池的寿命？ | |
| [答：] | The circuit is complex to adjust the charge current real-time. In oder to achieve effective solution and longer battery life, a limited charge current is used at the constant current mode for the charger. | |
| [问：] | 設計smbus充電器,可以由smbus讀出電池狀態來控制,充電器只需控制pwm是否可以? | |
| [答：] | In general, it is. However, there is interactive between the battery status and the battery charger. | |
| [问：] | 是否提供一揽子“傻瓜式”解决方案？ | |
| [答：] | We will offer a demo board for customer evaluation. | |
| [问：] | 是否有脉冲充电的方案？ | |
| [答：] | Yes. Pls contact our sales office for further information. | |
| [问：] | 手机锂电池经常会出现待机时间短的问题，请问这是为什么？（充电时是用认充充电的） | |
| [答：] | If the battery is used for a long time, it may be aging issue. | |
| [问：] | 手机在平时充电的过程中，若一直超过要求的2-3小时，会对锂电池有什么影响？ | |
| [答：] | It will shorten the battery life. | |
| [问：] | 手机中的锂离子电池在充电过程中处于开机或者使用手机状态，在与充电座接触不稳而导致短时间内几次充电过程断开和恢复，那么锂离子电池是否会产生一个时间很短的而较大值得峰值电流而导致手机主板烧坏？ 锂离子电池在充电过程中使用需要注意哪些事项？ | |
| [答：] | The max. charge current should be limited during the circuit design. So, this issue should not be happened. | |
| [问：] | 輸入電壓范圍 | |
| [答：] | 4.5V-6.0V | |
| [问：] | 随着输入电压的增加，控制电路的压降随之增加，如何控制功耗？ | |
| [答：] | If the heat dissipation is your major concern, then you can reduce the current in order to keep the power loss in the circuit. Otherwise, the higher efficiency circuit will be used, e.g. switching regulator. In general, the higher voltage difference between input and output of a linear power supply will get lower lower system efficiency. | |
| [问：] | 它采用什么技术呢 | |
| [答：] | CMOS process | |
| [问：] | 同一芯片能否通过芯片控制，对于不同的电池采用不同的充电模式？ | |
| [答：] | Yes, it can be. | |
| [问：] | 为什么要限流？大电流充电对锂电池会造成什么样的损坏？ | |
| [答：] | Larger charging current will damage the battery permanently. | |
| [问：] | 我的数据采集系统想从USB端口获取电源,MCU是TUSB3210,AD是ADS8323YB,最好还能给LOADCELL提供10V(50mA)电源,用什么方案比较好;谢谢! | |
| [答：] | You may use a boost or buck converter to regulate the volatge for the sytem. It depends on the required supply voltage and current of MCU and the other device. Pls contact our sales office for more the technical support. | |
| [问：] | 我公司的新开发产品打算分为两个部分,显示、按键等与客户交流多的部件放在手持部分，通讯、打印等大型部件放在座机部分，手持机配备了锂电池，由座机充电。但在应用中手持机拿离座机操作的时间很短，多数时候都会放在座机上充电，我想知道这样的情况该怎样选择充电方案？怎样保证锂电池的寿命?谢谢! | |
| [答：] | It like a Notebook PC with docking base. So, its circuit should be same as the normal battery charger. | |
| [问：] | 我是设计手机的，我想知道怎样保证在射频电路瞬间功耗很大的情况下怎样从电路设计上保持电压的稳定？ | |
| [答：] | In order to support a large transient current, usually a larger output and input capacitor is used to provide this transient power. Another way is used a power supply with higher output power. | |
| [问：] | 我想知道何谓便携式设备充电技术？它会给我们的生活带来那些好处？它对我们的生活会有什么影响？ | |
| [答：] | The battery charger is designed for the portable application. So, it should be small and efficiency. Usually, the portable product use single cell Li-ion.The max. battery voltage is around 5V.The portable product will increase our productivity and communication. The best example is cellular phone. | |
| [问：] | 现在USB电源线一般是5v,所以用USB给锂电池充电的电池一般是4.2或4.1v的,不知道有没有内置升压电路可以给7V或12V锂电池充电的,毕竟4.2V的电池功率是很难满足很多大功耗的移动设备. | |
| [答：] | It could be found in the market if there is demand on it. | |
| [问：] | 现在便携式设备充电技术上哪些公司处于世界领先！ | |
| [答：] | In general, different companies have different roadmap. NS is one of analog technology leader in this market.We focus to integrate those circuit into a single chip. | |
| [问：] | 现在已有的充电设备的最小电压及其他参数，请告之 | |
| [答：] | 1.2V rechargable Ni-MH. | |
| [问：] | 新推出的产品哪些？主要的技术特点？ | |
| [答：] | LP3945/46 and LP3938 is the new products. The major advantages is: a. the pass transistor is intergated. b. The package is small chip scale package.c. all the necessary chargering circuit is integrated into a single chip. | |
| [问：] | 需要以脉冲方式快速充电时，怎样使充电电流既符合快速充电的要求，又不会引发管理芯片的过流保护功能？ | |
| [答：] | A peak current is limited to make sure that it will not trigger the overcurrent protection circuit. | |
| [问：] | 演示中所示的充电时间5.6小使如何确定？有无计算方法？ | |
| [答：] | Built-in 5.6hour timer in the device. | |
| [问：] | 用USB供电，电流够吗？ | |
| [答：] | The USB power could provide upto 500mA current. | |
| [问：] | 有没有7ah,12.3V, 3节锂电池组的充电方案，或相应的设计思路，及需注意大地方？谢谢 | |
| [答：] | Yes. Pls contact our Sales office for further information. | |
| [问：] | 有没有能够充24V的，现在很多微型打印机用24VDC？ | |
| [答：] | LP3945/46 | |
| [问：] | 有没有完整洁的应用方案下载。 | |
| [答：] | Pls contact our Sales office. | |
| [问：] | 有无锂电池和镉镍电池兼顾的充电集成电路 | |
| [答：] | We have this device. Pls contact our Sales office for further information. | |
| [问：] | 在NS的网站上找不到LP39XX的有关资料，哪里有？ | |
| [答：] | Pls contact our sale office. | |
| [问：] | 这跟手机的发展有没有什么重大的影响呢 | |
| [答：] | It will help to reduce the size of mobile phone. | |
| [问：] | 这种’崭新的便携式设备充电技术‘对固体铅酸蓄电池是否有用？ | |
| [答：] | It is for Ni-MH and Li-ion only. | |
| [问：] | 这种可充锂离子电池充电后，可以连续工作多少小时？ 其使用寿命是多长时间？ | |
| [答：] | It depends on the battery capacity. | |
| [问：] | 终止充电电压误差对充电容量的影响,是终止电压偏大影响大,还是偏小影响大. | |
| [答：] | It depends on the battery chemistry. In general, higher battery voltage for end-of-chager is worst. | |
| [问：] | 专家好:现在国内锂电池主要使用还是在高端设备，大量民用设备还是采用镍铬或镍氢电池，不知道现在欧美锂电池使用情况是怎么样？ | |
| [答：] | Similar situation in the other countries. Li-ion for high end portable product, e.g. Mobile phone, PDA, notebook PC and etc. | |
| [问：] | 作为便携式设备的充电设备，其体积、质量的发展趋势也必将随之变小， 不知专家对： 1、“便携式设备的充电设备与便携设备的一体化的发展趋势做怎样的预测？” 2、“未来会不会出现，与ATM提款机类似的，在街头出现的能够为多种设备充电的公共充电装置！” 谢谢专家的解答！各位专家辛苦啦！ | |
| [答：] | 1. The charger circuit is already built in most of the mobile phone now.However, the AC adapter is still external.It is because its size is bulky.2. Possible but not necessary. It is because the charger circuit will be built in the portable equipment. | |
美国国家半导体致力开发各种高能源效率的模拟及混合信号半导体产品。该公司的PowerWise®系列产品旨在降低系统功耗，延长电池寿命，以及减少散热需求。美国国家半导体总部位于美国加州圣塔克拉拉(Santa Clara)，截至2008年5月25日为止的2008年财政年度的营业额达18.9亿美元。欲查询美国国家半导体的公司资料及产品信息，欢迎浏览该公司的网页，网址：www.national.com。
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