在线座谈

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关于本次座谈

精彩问答

主题:汽车电子应用解决方案
在线问答:
[问:ivanjin] 你好,请问能否推荐适用工程车辆的电源IC,例如DC/DC. 对于电源的功率和电压特点,请给予一些选择的知道。谢谢! 
[答:Terry] We have too many choices. In the presentation, you may already see some, but due to limited time, we can"t go through every parts we have. So, depending on your application requirement, we can have more involved discussion to locate a good part for you. You can contact us (tlo@linear.com) directly for details.  [2005-11-16 10:48:04]
[问:32kmcu] LT1937无电流输出的检测保护,在电路出现问题的时候,输出电压将一直升上去,直到损坏芯片自身.请问LINER有关于这个问题的解决方案吗? 
[答:Dongyan] We have parts with open LED protection, such as LT3465 and LT3465A.  [2005-11-16 10:52:59]
[问:winhi] LTC6101的H桥电流检测用两只检测有什么优点,用一只在回地端检测不可以吗 
[答:Glen] Using two LTC6101s allows us to sense what is the direction of the current in the motor.  Using one LTC6101, the current sense is always positive, so we would need to know what switch is on. Also, sometimes putting sense resistors in the ground path is not desirable.  But yes, in the ground path, you could use one or two sense circuits.  Using two gives you polarity information.  [2005-11-16 10:58:24]
[问:ptldy] 请问有无输入4V-80V,输出5V/3A的简单芯片方案? 
[答:Dongyan] What is your input source?  We have LT3800 that can work from 4V to 60V.  [2005-11-16 11:00:01]
[问:yjs1112] 请说明有关SEPIC拓扑结构的情况,多谢! 
[答:Terry] SEPIC topology is based on Boost converter and use 2 inductor (can be coupled) and capacitor for the power conversion. This topology has some drawbacks as the MOSFET then see high voltage and current stress (Vds can see Vin+Vout, Isw is the sum of the input and output current). The inductors and capacitor will also contribute to the loss. So, high efficiency is not easily achieved.  [2005-11-16 11:00:41]
[问:shandong] 你们的芯片,最大被测电流,有多大? 
[答:Glen] There is no current limit.  It depends on the sense resistor, and the maximum input voltage of the sense amplifier.  For the LTC6101, I think the maximum is 4V, so a 1 Ohm resistor would allow you to sense up to 4A.  A 0.001 Ohm resistor would allow you to sense up to 4000A  [2005-11-16 11:02:01]
[问:32kmcu] 请问有类似LT3450那样驱动LED的芯片,输出是5V,-12V,+15的单片解决方案吗? 
[答:Terry] Our LTC3450 is quite unique and it is mainly for multiples of 5V (5V, 10V, 15V, -15V, -10V, -15 etc). For your application, you can try our LT3463 or LT3471 (with some simple diode-cap charge pump) depending on the current requirement.  [2005-11-16 11:05:07]
[问:yjs1112] 请说明LTC3703架构的主要特点,多谢! 
[答:Dongyan] LTC3703 is a synchronous step-down Dc-Dc converter. [2005-11-16 11:05:50]
[问:qian.song] 是否在输入宽范围波动情况下,输入稳定在一个固定值?? 
[答:Terry] I think this question is asking about the buck-boost converter that we discussed in the presentation. Yes, we can provide stable output even though the input is very wide range. For input variation, it is a matter of line regulation, we have very good line regulation for many of our controller parts  [2005-11-16 11:06:34]
[问:zclong008] 请问凌特公司的电源半导体IC 在汽车电子方面相对于NS ,TI 等IC, 有什么优势? 
[答:Terry] We provides very high performance analog products and it is hard to generally provide a simple comparison for our advantage. If you have some specific requirement, I can give you something then and you"ll obviously see our advantage.  [2005-11-16 11:10:04]
[问:yjs1112] 请解说高性能降压型控制器-LTC3703的特征,多谢! 
[答:Dongyan] It can work up to 100V input voltage. It has 100kHz to 600kHz programmable freq.  It has dual N-channel MOSFET synchronous drive.  Please refer to datasheet for more details.  Our website is www.linear.com  [2005-11-16 11:10:09]
[问:dengxc] 请问专家:目前,在汽车电子领域中以经考虑的没有得到解决的问题有哪些? 
[答:Terry] There are so many different problems indeed. We"ve just covered some in our presentation.  [2005-11-16 11:13:46]
[问:lhpwell] 对汽车音响上的电源比如TFT显示上的变压器用途不一样吧?在我们的汽车音响上使用是怎样的? 
[答:Terry] I don"t think there is too much difference. Some difference, if there is, maybe on the input voltage range or product operation temperature range. Some maybe form factor (size).  [2005-11-16 11:15:50]
[问:Sy_Bngd] 什么是负载突降? 
[答:Terry] 负载突降指的是在交流发电机给电池充电时电池电缆断接的情形。这种突然断接可能产生高达60V的瞬态电压尖峰,因为交流发电机试图给电池完全充电。交流发电机上的瞬态电压抑制器通常把总线电压箝位于36V和60V之间,因而使得交流发电机的下游器件主端DC/DC转换器能够承受60V的瞬态尖峰。由于希望这些转换器以及由这些转换器供电的子系统在瞬态事件发生期间和发生以后正常工作,所以DC/DC转换器能够处理这种高瞬态电压是至关重要的。  [2005-11-16 11:16:07]
[问:yjs1112] 请说明面向汽车应用的LED驱动器状况,多谢! 
[答:Dongyan] More and more LEDs will be used in car: such as auto dashboard, LCD panel backlight, interior light, brake light.  Our company has a large variety of parts that are aiming at driving high power LED: LT3474, LT3477, LT3479, LT3486...  [2005-11-16 11:17:30]
[问:dragontan] 在汽车电子中使用的电源模块,你们都做了哪些改进?在转换效率,纹波率方面,散热方面,你们可以做到什么程度?谢谢 
[答:Terry] We"ve done a lot. We are always trying to provide the best efficiency, lowest noise and small solution to the market. Some techniques we are using is very confidential but I don"t think customer needs to care so much. Just try our part and you"ll see how good it is!  [2005-11-16 11:18:18]
[问:yjs1112] 请说明陵特公司的高效率解决方案,多谢! 
[答:Terry] We have too many. So, it is hard to give a very general explanation. Do you have anything specific?  [2005-11-16 11:20:29]
[问:qbw] LTC6101能否程控输出正、负400MS的3A/24V电流? 
[答:Glen] No.  The LTC6101 can only sense current in one direction.  You can use two of them to sense current in both directions.  Or, you can use a two-direction sense amplifier like the LT1787. The 400ms is not a problem.  Both LTC6101 and LT1787 are fast enough.  [2005-11-16 11:22:03]
[问:wfm] 请问LTC3701提供3.3伏和1伏的电流可以最大多少? 
[答:Terry] LTC3701 is an old part. The newer part that may perform even better is LTC3737. Anyway, the answer to your question is - depending on the external component choice. We"ve built application to can support up to 4A.  [2005-11-16 11:22:14]
[问:zclong008] 请比较一下LED 窜联驱动和并联驱动的优缺点!谢谢 
[答:Dongyan] If you put the LEDs in series, you don"t need to worry about balancing the LED current, the circuit is simpler.  However, the number of LEDs will be limited by the rating of the switch pin voltage. If you put the LEDs in parallel, you can drive more LEDs, however, you need to ballast the currents.  We have parts like LT3486, LT3466, LT1942, which can drive multiple strings.  [2005-11-16 11:24:03]
[问:ptldy] 芯片的输入上限是60V,具体如何在输入端加器件抑制60V以上的干扰脉冲? 
[答:Terry] Frankly, we can"t! You need to use some other voltage suppression device. TVS is one commonly used. The reason why we have 60V is to leave more rooms for the protection device. In fact, you won"t have continuous 60V but spike or noise can go all the way up. Therefore energy absorbing device like TVS should be used to clamp the voltage. However, when you take a closer look on the specification TVS, the clamping range of those devices are quite wide. You can easily see a 24V device that have maximum clamping voltage of 58V if maximum current is pumpped to the device (energy indeed). So, a higher input range for the power supply can increase the reliability.  [2005-11-16 11:25:58]
[问:maomaocong] 可否采用瞬态电压抑制器来应付负载突降? 
[答:Terry] 在外部加设瞬态电压抑制器实施电路保护是一个可行方法,但是这些电路增加了成本并需要占用宝贵的电路板空间。凌特的高压开关稳压器能承受高达60V的瞬态电压,同时在不对系统性能或可靠性造成影响的前提下维持输出稳定。一般情况下,这些稳压器都是降压型或降压-升压型转换器,可经受由充电/电池系统中断引起的汽车电池和交流发电机的电压置换。  [2005-11-16 11:26:02]
[问:kevinlee] 有没有轮胎压力和温度检测方面的? 
[答:Terry] It all depends. What specific standard and what sensor do you have? We may have some application circuits that can help.  [2005-11-16 11:27:06]
[问:mahatma] Linear 对现在新型白光LED驱动有没有更好/或者说是效率更高更简洁的解决方案? 
[答:Terry] Yes, we have and indeed too many. So, what power do you need, how many LEDs will you use? What color are they?  [2005-11-16 11:27:53]
[问:32kmcu] 请问申请样片的最小交货周期是多长时间? 
[答:Terry] We have a sample site www.linear.com.cn in China and we usually can deliver samples in 2 days if stock is available.  [2005-11-16 11:28:47]
[问:MSS_SZ] 请问LINEAR公司在2006年还会推出哪些新的汽车电子器件? 
[答:Terry] We have around 200 new parts a year. It is hard to tell what parts we are going to launch. What kind of product are you interested in?  [2005-11-16 11:29:28]
[问:dragontan] 请问你们芯片可否用OrCAD仿真,请问芯片资料在哪里可以下载,谢谢 
[答:Terry] We don"t provide OrCAD simulation. However, our SwitcherCAD is a SPICE base simultation tool that may be useful for you in designing with our product.  [2005-11-16 11:30:07]
[问:yjems] 请问演示中介绍的产品是否已经量产?哪些被汽车企业或者配套企业实际采用过? 
[答:Terry] The products are all released and in mass production. I"m sorry that I can"t tell you who my customers are.  [2005-11-16 11:31:01]
[问:gary868] 能說說白光LED驅動器的最佳配置嗎? 
[答:Terry] I don"t quite understand the question. Can you be more specific?  [2005-11-16 11:31:39]
[问:yjs1112] 请解说目前在电子汽车领域电源设计面临的挑战如何,多谢! 
[答:Terry] There are so many challenges, we have covered some of them in the presentation.  [2005-11-16 11:32:06]
[问:32kmcu] LT3736的SGNG要多点连接后一点接入PGND,为了避免将谐波带入PGND,那么可否将SGND多点连接后经一铁氧体电感接入PGND?这样做有好处吗?如果有害处,主要体现在什么地方? 
[答:Dongyan] The important thing is to keep the small signal stuff seperate from the power planes with a local SGND trace or plane.  You don"t need to use an inductor.   [2005-11-16 11:32:30]
[问:qbw] 在LED供电时为提高效率,如何进行限流? 
[答:Terry] There are many methods to do the current control, depending on the topology and the way you connect the LEDs. How many LEDs do you want to connect? How do you connect the LEDs? How much power are the LEDs? What is the input source and voltage range?  [2005-11-16 11:33:25]
[问:td_wang] 一个开关稳压器用于汽车导航系统时,需要具有那些特点? 
[答:Terry] 通常开关稳压器在汽车导航系统应用上需要具有(1)宽输入工作范围,(2)在宽负载范围内的高效率,(3)在正常工作、备用和停机时具有低静态电流,(4)低热阻,(5)低噪声和低EMI辐射,(6)负载突降抗毁性。  [2005-11-16 11:34:39]
[问:yjs1112] 请说明新款的高电压降压型稳压器的优点,多谢! 
[答:Terry] High efficiency, robust, small form factor, simple circuit. Just provide good and stable voltage that you want.  [2005-11-16 11:35:41]
[问:tjwdb] 十年前曾在汽车上使用LM7805,结果被瞬间高压打坏,后来加上过压保护得以解决,想知道这样的问题你们使用什麽器件解决。刚才的演讲中提到有一款产品可以抑制宽范围电压波动,我的理解是不是可以省掉过压保护器件,如TVS,谢谢! 
[答:Terry] No, TVS is still needed. I think I"ve provide some insight in my answer to another question here. So, in general, the TVS has very wide range of clamping voltage. So, a higher input range power supply can help to ease the TVS selection and provide higher reliability.  [2005-11-16 11:37:02]
[问:32kmcu] 如果我使用LTC1669的DA输出来控制LTC3736的VFB2脚,那么对于此路输出电压是否可以达到关断的效果? 
[答:Dongyan] Can you use pin 14 or pin 17 to turn off the output?  [2005-11-16 11:37:55]
[问:fcl-cq] 请问在重庆市区的销售地点和代理公司名称 
[答:Terry] We have Arrow, Avent-Memec and Cytech in Chengdu.  [2005-11-16 11:37:59]
[问:qiyu] LTC3780可以写程序吗? 
[答:Terry] No, this is totally a hardware power supply. No software needed.  [2005-11-16 11:40:40]
[问:hzj515] 可否提供LT3479相关资料和样品 
[答:Terry] Yes, can you provide us your email address? You can also download our datasheet at www.linear.com  [2005-11-16 11:41:12]
[问:johnren] 请问DC-DC的BOOST模块中,L和C的选择应注意哪些问题,在后级的退藕中为提高PSRR应主要抑制开关的基频吗? 
[答:Dongyan] In boost converter, there are difference criteria about selecting L.  The most basic one will be having the inductor ripple current at about 30% to 40% of the DC input current.  The output capacitor will be selected basic on the output ripple requirement, load transient response requiremnet and loop stability.  [2005-11-16 11:41:12]
[问:robin] 可否采用瞬态电压抑制器来应付负载突降? 
[答:Terry] 在外部加设瞬态电压抑制器实施电路保护是一个可行方法,但是这些电路增加了成本并需要占用宝贵的电路板空间。凌特的高压开关稳压器能承受高达60V的瞬态电压,同时在不对系统性能或可靠性造成影响的前提下维持输出稳定。一般情况下,这些稳压器都是降压型或降压-升压型转换器,可经受由充电/电池系统中断引起的汽车电池和交流发电机的电压置换。  [2005-11-16 11:41:15]
[问:wwwcom] 请问专家: 1.对蓄电池冲放电如何管理? 2.配电如何管理? 3.有没有电源系统智能化控制的解决方案,比如自身状态检测、故障定位、故障恢复。 4.dc/dc集中变换和分散变换那一个好一些 5.对10~40w的DC/DC林特有解决方案吗 6.如果是太阳能提供动力的汽车,如何对多余的太阳能进行分流  
[答:Terry] These are very general questions and our answer is: it all depends! We need more details in order to under the requirement. We have quite a number of solutions that may be suitable, but just not easy to put a simple answer here.  [2005-11-16 11:45:17]
[问:yjems] 凌特是否提供电源器件在汽车应用方面的参考电路,比如小电流检测、轮胎压力检测等?如何获取/ 
[答:Terry] Can you be more sepcific? How small current do you want to detect? High side sensing or low side?  [2005-11-16 11:45:52]
[问:yjs1112] 请说明LTC3780与LTC1871 SEPIC之间的有缺点,多谢! 
[答:Dongyan] LTC3780 has advantages in efficiency and external component sizes. As we mentioned in the seminar, both the switch currents and voltage stressed during off-time are much less in LTC3780.  Therefore, the efficiency is much higher and we can use only one inductor with lower current rating.  [2005-11-16 11:46:20]
[问:kkwd] LED驱动的功率是多少,用的什么方式升压? 
[答:Terry] It depends on how many LEDs and how much power you want to power up.  [2005-11-16 11:46:25]
[问:h458] 请问在厦门的代理公司的名称\电话? 
[答:Terry] Arrow: 0592-2394567 Cytech: 0592-5638488 Avent-Memec: 0592-5164701  [2005-11-16 11:49:27]
[问:zhoujiang100] SEPIC方案是不是就是讲能根据输入电压来自动升压或降压?谢谢 
[答:Terry] Yes, it is. This is done by topology.  [2005-11-16 11:50:53]
[主持人:ChinaECNet] 恭喜您, 华睿科技的lxs经过电脑抽奖您在本次座谈中获得一部MP3播放器。请网名为lxs的用户与中电网联系(8610-82888222-7008 或 lilin@chinaecnet.com)。  [2005-11-16 11:51:34]
[问:qbw] 哪一种芯片能吸收电感负载的回馈的能量? 
[答:Terry] I think this is asking of whether we can sink current. We have some DDR part that has the ability to source and sink current. You can visit our website to take a look on LTC3413, LTC3717 etc.  [2005-11-16 11:52:55]
[问:pengq318] 请问LINEAR在电流控制方面,如:恒流/过流保护方面有没有?有何特点?谢谢 
[答:Glen] Yes, for example we have LT1970, which is an opamp with adjustable current limit.  Also, we have "circuit breaker" chips such as LTC4213.  [2005-11-16 11:53:43]
[问:yjs1112] 请说明凌特公司在汽车电子领域的卓越贡献是靠什么取得的,多谢! 
[答:Terry] High reliability, good solution, robust system, innovative products, good delivery and technical support.  [2005-11-16 11:55:24]
[问:yjs1112] 请谈谈面向汽车应用的电流检测放大器的特征,多谢! 
[答:Glen] Often the most important specification in automotive is the operating temperature range.  The LT6100 and LTC6101 have full automotive operating range of -40 to 125C.  Also important is fault and overvoltage handling.  Both parts can tolerate large differential input voltages.  The LTC6101 is also available in a 105V version.  [2005-11-16 11:58:03]
[问:qbw] LTC6101电流检测的采样电压最大为多少? 
[答:Glen] The maximum differential input voltage is determined by the input resistor.  With a large resistor you can have a larger sense voltage, but the accuracy at small voltages will degrade. The maximum supply voltage is 105V for the "HV" high voltage version.  Otherwise 70V max supply.  [2005-11-16 12:02:30]