在线座谈

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关于本次座谈

座谈简介

前所未有的数字信号处理技术

精彩问答

座谈主题:数字电位器的原理及基本应用
在线问答
[问:gqt] 数字电位器是否可用作具有线间电压为15伏的取样电阻,并由其实现程控电源输出电压? 
[答:Alan_Li] AD5260,5262,5263, 5280,5282, and AD7376 can all handle +15V  [2003-1-14 10:35:52]
[问:pichair] 请问数字电位器的控制宽度可以调节吗? 
[答:Liao_ Wen_Shuai] What does 控制宽度 mean? If it means the resolution, then the resolution is fixed. If you mean the total resistance, we have a lot of choice in this aspect. If you want to know more, send mail to china.support@analog.com or call the toll-free number 800 810 1742.  [2003-1-14 10:37:12]
[问:jyw] 我们会使用到各种类型的传感器,数字电位计能否都适用,请举例详细说明传感器校准原理,并提供所元器件的相关资料。 
[答:Char les_Lee] Mostly, it dependent on the voltage and current on the transducer side. Not all of the digital POTs can use on all of the application. For your second questions, please contact our local office for more details.  [2003-1-14 10:39:45]
[问:杨兵] 是否可以用于自动化的模拟量控制,其通道有几组?原理图是否可以提供.规格型号和技术要求?温度和海拔的影响?谢谢~~~! 
[答:Eagle _Zhang] We have AD5203 (4 channel), AD5206 (6 channel) Digi-Pot that can used in Analog input as the presentation says. Please contact ADI local office to detailed discuss.  [2003-1-14 10:43:16]
[问:gxg] 电位器的线性特点随着加在两段的电压而有所变化,这样在具体应用中,将如何保证数字电位器的线性精度?因为在使用中,电位器的端电压保持恒定的机会比较少。列如:如何在程控电源中使用数字电位器?若用作采样电阻,则端电压将不可能不变化。 
[答:Liao_ Wen_Shuai] In fact, ADI has done many to improve the linearity during manufacturing. Also, we have provided a way in the presentation in page 13. To be simple, connect a precise resistance with the digi-POT will be helpful.  [2003-1-14 10:44:24]
[问:wjt814 @183.ha.cn] 我知道其基本原理,但是如果采用电压控制其增益的大小,那么当电压波动或控制管参数变化那会把数字点位器影响效果怎么样???不到只处,见谅!
[答:Alan_Li] No, because the switch uses transmission gate which minimizes signal modulation. However, to preserve min distortion because of wiper resistance effect, the gain usually limited to 10.  Higher gain requires 2-stages.BW is also concern, the lower the rated RAB, the higher the BW.  [2003-1-14 10:45:32]
[问:dn maoyong] 请问,数字电位器是通过与处理器芯片进行数据交换来调节电阻值的吗,如果是,那请问数据交换方式是串行还是并行 
[答:Charl es_Lee] It use the serial method(SPI or I2C) to program the digital POTs.  [2003-1-14 10:47:08]
[问:lxyzhy] 数字电位器目前最小单级电阻是多小?应用数字电位器怎样来达到模拟线性电路要求的电气参数的线性变化?单级电阻是不是越小越好? 
[答:Liao_ Wen_Shuai] ADI has a lot of choice in the digi-POT. And has the most precise digi-POT in the world 1024. So the minimal will be the total resitance/1024.For the second question, refer to page 13. To connect a shunt resistance with high tolerance will be helpful.No. For the linearity is decided by the material to make the resistance. The most important is the wiper.  [2003-1-14 10:48:57]
[问:lao wu_z] 能否在电子电位器上增加类似watchdog的装置来监视电位器的跑飞现象,以减轻MCU的负担,保护电路的安全? 
[答:Char les_Lee] Yes, this is the way for those digital POTs with EEPROM inside. Because during the programming the EEPROM, once the power supply down to some certain levels, it can interrrupt the MCU.  [2003-1-14 10:49:46]
[问:Hado] 如何保证数字电位计在规定的温度条件下输出飘移问题。 
[答:Alan_Li] Two choices:Poly resistance pots typically have 300ppm/C TC.Thin film pots (such as AD5235) typically have 35ppm/C TC.In addition, if using pot in "Potentiometer mode" TC will be further reduced because RWA and RWB resistance change in ratio and therefore TC track each other. [2003-1-14 10:50:03]
[问:Geison] 1、控制精度或步长?2、初始值如何保存?上电默认值如何确定?3、与机械电位器的成本对比、可靠性对比。4、在步进控制过程中,数控电位器比数控电压、电流器的优势在哪里? 
[答:Eagl e_Zhang] 1. control determined by the steps, we have AD5203 (64 set) /AD5206 (256 step ) / AD5235 (1024 step), etc. That is, the setep = Max Resitor / number of steps.2. If you use Nonvolatile type such as AD5235 Nonvolatile Memory, Dual 1024 Position Digital Potentiometers, then the previous will be load in to the WAP automatically when power on. (Refer to datasheet).3. The cost is almost the same as the 多圈电位器, 但可靠性高很多。4、这取决于控制方式。  [2003-1-14 10:50:21]
[问:chen yunhn] 本人对数字电位器不是很懂,由于工作需要,想了解“数字电位器在测量放大器中的一些应用”,非常感谢!!! 
[答:Char les_Lee] You can use it to program the Instrumentation amplifier"s external gain resistor Rg. Please refer to the AD623 data sheet for the detail schematics.  [2003-1-14 10:51:35]
[问:hebeit angshanlu] 1、数字电位计在传感器校准、偏置控制领域内的应用有何明显的优势?2、它的转换精度和转换速度能达到多少? 
[答:Liao_ Wen_Shuai] 1. It can be controlled via the micro-controller in the system. So it will be convenient to be used in the automatic process and other application.2. The most precise is 1024. The settling time is in the micro-second degree. Refer to page 17 in the presentation.  [2003-1-14 10:53:45]
[问:Rober tLiang] 我曾经有意将数字电位器X9511用于电源电压的调整电路,但发现其工作电流很小,小于10mA,因此没有采用。请问如何将数字电位器用于工作电流较大的场合? 
[答:Way ne_zhou] You can refer to page 15, adding a FET can help you. Also you can choose ADI potentiometer AD5220 which has 128 resolution.  [2003-1-14 10:54:15]
[问:merrylq] 请问工程师:   我想问一下关于使用数字电位器来组成可编程电阻的问题,其中的问题就是:数字电位器允许的电流很小,如何给它扩流;谢谢!! 
[答:Alan_Li] Using pot to control the gate of the MOSFET can yield higher current through the low MOSFET resistance. However, it"s for certain applications only. Please send email to digital.pots@analog.com we will send you more tips. [2003-1-14 10:54:36]
[问:qin] 数字电位计中的电阻是用厚膜电阻还是用薄膜电阻制成?它们的温度系统如何?高精度的数字电位计是否要进行温度补偿? 
[答:Liao_ Wen_Shuai] ADI provide the resistance made with the thin-film and poly resistor. Their temp cof. is can be found in page 12. whether compensation is needed is decided by the usage. Also, you can find this information in page 12.  [2003-1-14 10:56:48]
[问:xkw1cn@ yahoo.com.cn] 如何抑制数字电位器在滑变时的噪音 
[答:Peter _Kh] You can reduce the noise by using a pot with the lowest end-to-end resistance.  Also, you can place a high freq. cap at the w terminal to filter out noise.  [2003-1-14 10:57:29]
[问:xiao ren0533] 数字电位计的控制方式有那几种?比如我现在用的数字电位计是3线制控制的,我想知道是否有其他的控制方法
[答:Char les_Lee] you can use SPI or I2C to control it.  [2003-1-14 10:57:45]
[问:wll9900] 请问怎样应用数字电位器来完成电源的DC-DC转换,如+9V转换成+5V. 
[答:Peter_Kh] You can use a high voltage 15V part such as the AD5282 or AD5262 in the voltage divider mode.  Then adjust the wiper 1/3 scale to achieve 5V.  [2003-1-14 10:58:21]
[问:zhxchen @163.com] 是否有样片可申请?ADI在大陆地区有哪些代理商? 
[答:Way ne_zhou] Please send your sample request to ADI distributor as Excelpoint, Chinatronic, Arrow, Future and WPI. Also you can register on myanalog at www.analog.com, then you can apply sample from ADI directly via web.  [2003-1-14 10:58:57]
[问:bill_cd @163.com] 请问如果将数字电位器用于可变增益的音频放大,那么他的指标能够达到多少(比如THD+N和频率响应)。 
[答:Alan_Li] Digital pot can used directly in gain path but some designs is better to put the pot should be used as an front end attentuator and then used "fix gain" amp to step up the gain.THD is code dependant and it typically ranges from 0.005% to 0.5% in various codes.  [2003-1-14 10:59:51]
[问:181wh] 请问数字电位器可调节多高频率的电压信号? 
[答:Char les_Lee] 1 MHz @ full scale input. But if you redeuced signal swing that you can reach higher BW. normally, if signal is small enough, 10MHz is achieveable but you will lose the resolutions.  [2003-1-14 11:01:52]
[问:liuy ongtao] 在控制系统中,我能否采用此芯片作为一种模拟量输出,去控制其它的元器件动作? 
[答:Char les_Lee] Yes, you can used the digital POTs as the DAC.  [2003-1-14 11:02:26]
[问:sunyt] 数字电位器能否提供高压的产品? 
[答:Char les_Lee] Yes, ADI parts can works up to 30V maximum. Please contact our local office for details.  [2003-1-14 11:03:09]
[问:ljp] 一般来说,机械电位器用作音量控制不会产生附加失真。数字电位计对信号失真有无增加?如何选择数字电位计? 
[答:Liao_ Wen_Shuai] This is code dependent, the range will from 0.05% to 0.5%. In order to select the right digi-POT, ADI made a chart for it. Refer to page 9 of the presentation.  [2003-1-14 11:05:13]
[问:czsjm] 是否有关数字电位器在电机(无刷电机)控制中的典型应用图。 
[答:Charles_Lee] Sorry, we don"t have this schematics. But you can call to our local office for more details.  [2003-1-14 11:06:51]
[问:janeh ao_0101] 机械电位器分A,B,C等不同曲线,数字电位器是否可以做到,这点作音频控制时是必须的 
[答:Liao_ Wen_Shuai] Digi-POT is linear. So it can reach your target. Refer to page 39 of the presentation.  [2003-1-14 11:07:30]
[问:ljp] 数字电位计用作移相器,相位移动有多大?能反相吗(移180度)? 
[答:Eagl e_Zhang] 请按普通可变电阻来考虑移相问题, 但请注意数字电位器频率响应只有1M左右。  [2003-1-14 11:09:16]
[问:lzq6889 @sina.com] 在某模数转换设计中,利用数字电位器完成放大器放大量的调整,产生了很大的噪声,影响AD变换。最后,不得不使用机械式电位器。请问:怎样避免或者抑制噪声的产生? 
[答:Eric_liu] I don"t recommend digital potentiometer applied as a front-end signal-conditioning device before high speed,hight accurate ADC.Maybe you can try AD523x.  [2003-1-14 11:09:20]
[问:lddqzj] 是不是可以这么理解:不使用MCU就无法直接使用数字电位器? 
[答:Liao_ Wen_Shuai] No. For some digi-POTs you can control them manually, AD5220 for example. Also, refer to page 9, please.  [2003-1-14 11:09:43]
[问:xiao ren0533] 请问,数字电位计的抗干扰性能怎样?在使用中是否会发生电阻变化的情况? 
[答:Way ne_zhou] As digital poetentilmeter is active device, its anti interference is worse than mechnical part. However, digital potentilmeter is relatively insensitive to vibration, and it"s easier to remote adjust with higher resolution, and some else advantages, which you can refer to slide 5 of the seminar.  [2003-1-14 11:11:22]
[问:qin] 数字电位计用作增益控制时,它的带宽应比被控制的大多少才算成本效率的? 
[答:Char les_Lee] This is dependent on the signal swing. For small signal, up to 5MHz is good enough for the application.  [2003-1-14 11:11:47]
[问:dnmao yong] 断电之后,数字电位器的阻值能保持吗?
[答:Liao_ Wen_Shuai] This is decided by the digi-POT you selected. When power down, the resistance will be diminished. After power up, the resistance will be restored if it is a digi-POT with involatile memory, AD5235 for example.  [2003-1-14 11:12:01]
[问:wy56] 我公司位于广东省的珠海市,为了减少采购的中间环节,应该向哪间公司购买AD的数字电位器产品?是否可以提供技术样片? 
[答:Eric_liu] you can call 0755_83165141 .shenzhen superfly co.,ltd.We provide you samples.You can apply at www.analog.com or call us.  [2003-1-14 11:12:33]
[问:dfli] 数字电位器电阻值的精度是多少?有些品牌的大约是25%,如100k+25%、100k-25%、ADI能做到多少?是什么原因造成的? 
[答: Alan_Li] slide 13 discuss the reason because the thickness, measured in um, is very challenging to control.slide 13 also illustrate a trick to reduce its tolerance but in potentiometer mode.Using higher resolution pots may also make up the deficiency of poor accuracy in some applications. [2003-1-14 11:12:51]
[问:lq_lily] 为何同类数字电位器在同样的控制条件下,上电的初始值不一样? 
[答:Way ne_zhou] Then you must be using volatile digital POT. If you want a fixed figure of the resistence when power on, please use involatile POT, or OPT kind of digital POT. You can refer to slide 8 of the seminar.  [2003-1-14 11:13:23]
[问:qin] 数字电位计的工作速度能达到多少?特别是用作激光二极管调制器更是如此。 
[答:Eagle _Zhang] 1~10uS左右的设定时间,足以用作激光二极管调制器的功率,消光比的设定。比如,ADN2841/7 (LDD) + ADN2850 (1024 step Digi-pot), 用ADuC814(6AD + 2DA + 8052MCU + 8K Flash memory)来控制。  [2003-1-14 11:13:54]
[问:bslk5] 请问:键控数字电位器的调整在极值时,是循环变化还是停止调整 
[答:Liao_ Wen_Shuai] When the wiper hits the end of the resistor (Terminals A or B) additional CLK pulses no longer change the wiper setting.  [2003-1-14 11:14:13]
[问:tangmix] How about it"s respond speed? Dose it act quickly? 
[答:Peter_Kh] The response time depends on the load and the wiper setting of the digital pot.  Typical settling time is in the range of a couple micro seconds.  [2003-1-14 11:15:31]
[问:zhlzhz @sina.com] 请问数字电位器的切换速率上限可到多少?我关心她是否能用于实时控制? 
[答:Way ne_zhou] It"s on micro second level, so it"s easy to use as real time control. AD5273 is a good choice with high speed.  [2003-1-14 11:16:33]
[问: Anoymous] 当我关心电位器比率的温度稳定性能时,哪些方面需要考虑,可以使用哪些此性能高的器件?谢谢! 
[答:Alan_Li] Use thin film digital pot such as AD5241, 5242, 5260, 5262, 5280, 5282, 5263, and 5235 for lowest TC, 35ppm/C.If using the pot in "3-terminal potentiometer mode", even poly resistance (300ppm/C) will reduce significantly to say 50ppm/C because the pot becomes ratio-metric.  [2003-1-14 11:17:05]
[问:lddqzj] 数字电位器是否需要编程使用?就是说只有数字信息才可以正确的控制它?而模拟量的输入无法改变它的内部状态? 
[答:Char les_Lee] Yes. You have to use the MCU to control it.  [2003-1-14 11:18:38]
[问:sf-sensor] 请问数字电位器调节后是否可以锁定? 
[答:Char les_Lee] Yes, please use the parts with EEPROM inside. Such as AD5231/32/33/35.  [2003-1-14 11:20:04]
[问:louyun] 一个疑点:当其中一个单级电阻损坏时!系统如何检测到?如何保证输出是按要求在进行?谢谢! 
[答:Eagle _Zhang] 1. 数字电位器与几十欧电阻串联较好。2、一般数字电位器不会损坏,如ADN2850/AD5235 用LASER TRIM,不易损坏。3、因为ADN2850、AD5235 (Nonvolatile Memory, Dual 1024Position Digital Potentiometers)有非易失性内存, 上电、掉电时能保持已设定值。若想检测到控制电压是否正常,可以用ADuC814的ADC来检测。  [2003-1-14 11:20:28]
[问:guiling _chen] 控制电平是TTL/CMOS/LVTTL/OTHER? 
[答:Char les_Lee] TTL is most control level we used on the digital POTs.  [2003-1-14 11:20:33]
[问:liaojj] 本人用过数字电位器,我想知道你们的有哪些等级的电位器?怎么跟你们联系 
[答:Eric_liu] ADI have 1,2,4,6channel,32,64,128,256,512,1024 position resolution.3V to 30V,+-2.5V etc. supply operation digital potentiometies. More information can find at www.analog.comOr you can call 0755-83165141 superfly Ltd.  [2003-1-14 11:21:08]
[问:lif71] 我想选一款数字电位器:3.3V,3通道,I2C接口,10K欧,2美圆/片以内,请问ADI有无合适的。 
[答:Liao_ Wen_Shuai] Yes, you can select our 4-channel AD5263. Also, maybe you can consider AD5242 and AD5282, which are dual-channel parts.  [2003-1-14 11:21:14]
[问:tjs] 用数字电位器实现对数增益控制与D/A和可变增益放大器的方案,哪一个好些? 
[答:Way ne_zhou] Normally digital potentiometer has wider voltage output range, And digital potentiometer is cheaper. But DAC can have bigger current output and with higher resolution.  [2003-1-14 11:21:45]
[问:ljp] ADI的数字电位计中的存储器大多是那种类型的?有Flash的吗? 
[答:Char les_Lee] We used EEPROM inside not flash. The biggest memory size is about 100 bytes internal. You can used up to 256 bytes externally.  [2003-1-14 11:22:47]
[问:gxg] 用多个数字电位器串联能否得到较高分辨精度的数字电位器,例如我现在需要12bit分辨率的数字电位器,如何组合? 
[答:Eagle _Zhang] 理论上可以,但要考虑单调性。建议用带非易失内存的, 如AD5235。  [2003-1-14 11:23:07]
[问:dfli] 数字电位器的开关电阻在代码值较小时对设定的电阻值的影响较大,如用于调整放大器增益,将造成增益误差加大,如何接解决这个问题? 
[答: Alan_Li] Put digit pot in front end as attentuator rather than in the gain path, then with a fix gain amp for to achieve desirable gain.  [2003-1-14 11:23:23]
[问:zhlzhz @sina.com] 请问:数字电位器的英文是什么?我怎样才能从analog网上找到相关资料?我想下载。提个建议,像analog这样的大型网站,每次举行产品介绍,希望首先列出产品资料出处,已备查询。谢谢! 
[答:Liao_ Wen_Shuai] Digi-POT in English. You can find it by input the part number or digi-POT, then search in the ADI website. You can download it from our website. Also, you can send mail to china.support@analog.com to ask for the CD-R or call the toll-free number 800 810 1742 for help.In fact, you can get the materials from the ChinaEcnet or from ADI.  [2003-1-14 11:24:29]
[问:avr51 @163.com] 请问数字电位器的从输入数值到输出阻值的最短时间有多长?可不可以用于高速控制?
[答:Way ne_zhou] It"s depending on the input code. Normally it"s micro seconds level. But we"ve faster chip like AD5273 with 6MHz bandwidth.  [2003-1-14 11:26:09]
[问:ljp] 数字电位计的建立时间如何?如何挑选? 
[答:Eagle _Zhang] 一般1~10uS。请参考datasheet 或 与ADI联系。China Support Center free Call Number: 800 810 1742China Support Center free FAX Number: 800 810 1747ADI analog prodcuts China Support Center Email: China.support@analog.comADI DSP prodcuts China Support Center Email: China.dsp@analog.comSamples can be applied in www.analog.com, please register in myanalog first.ADI authorized Distributor: GEHK/Excelpoint Shenzhen office: +86-755 - 8364 0166Chinactronic/Avnet Shenzhen office:+ 86-755 - 8378 1886 Arrow Shenzhen office: +86-755 - 8359 2920Future Shenzhen office: +86-755 - 8366 9286WPI/WPG Shenzhen office:+86-755 - 8358 0555 [2003-1-14 11:26:34]
[问:louyun] 数字电位器是有级的调节,目前最高分辨率为多少?如何达到高分辨率接近无级? 
[答:Char les_Lee] 10 bits is the single chip digital POTs resolution we can reach. But you can used the extra external digital POTs to increase the resolution.  [2003-1-14 11:26:49]
[问:qin] 数字电位计中滑片开关能达50欧姆,能介绍它的结构和工作情况码? 
[答: Alan_Li] You must use an N-Ch Power MOSFET such as FDV301N or 2N7002 to achieve such low resistance. See slide 15. This application works only if A" is hold at a fixed voltage such as 1.2V from a controller IC.please send email to digital.pots@analog.com for further discussion  [2003-1-14 11:28:03]
[问:tn.l] 请问,如何提高数字电位器的抗干扰性能? 
[答:Liao_ Wen_Shuai] Just do like normal. You can use shielding, grounding and power technology to improve it.  [2003-1-14 11:29:39]
[问:yang_ xuefeng] ADI公司的数字电位器有无状态记忆功能?在掉电后再次上电时需要重新编程设定它吗? 
[答:Way ne_zhou] We"ve both involatile digital potentiometer, and one time programmable digital potentiometer, both can keep the position of wiper, when power on no need to re-program.  [2003-1-14 11:29:51]
[问: wuzhong] 请问最低电压可达多少?最低电流可达多少? 
[答: Peter_Kh] The minimum operating voltage is about 2.7V and the minimum supply current is 1uA.  [2003-1-14 11:30:56]
[问:林桥枫] 按钮控制式的数字电位器出现按钮按下次数及输出值与预测值不符时,怎办?
[答:Way ne_zhou] It may be button bounce problem, so please use ADM812 (reset chip) to de-bounce it. You can refer to slide 18 on the seminar file.  [2003-1-14 11:31:17]
[问:deyun] 数字电位器有使用485接口控制的产品吗? 
[答:Char les_Lee] No, but you can used the ADuC814 as the RS-485 receiver and used its SPI port to control the digital POTs.  [2003-1-14 11:31:24]
[问:zhy18 @163.com] 怎样解决可变电阻功率浪费的问题 
[答:Liao_ Wen_Shuai] In fact, the current is in several micro-Amperes. So the power dissipation can be negligible.  [2003-1-14 11:31:37]
[问:181wh] 上电后是否可读出电位器划动端所在的位置? 
[答: Alan_Li] Yes, majority of the digital pots settings can be readback through the SDO pin (SPI parts) or SDA (I2C parts).It readbacks the wiper setting but not the absolute resistance value.  [2003-1-14 11:31:57]
[问:tjs] Please compare your products with XICOR"s. 
[答: Peter_Kh] Our parts feature a much smaller die size with unmatched resolution.  Also, Xicor has been known to have some reliability issues with their non-volatile memory while we haven"t.  We also offer an extended operating voltage range up to 15V while Xicor is limited to 5V.  [2003-1-14 11:34:21]
[问:qin] 能否谈一下从单极转换到双极输出的上下对称性?即误差有多大?和那些因素有关? 
[答:Liao_ Wen_Shuai] Refer to page 33 of the presentation. The error is decided by the Amplifier and the resistors used in the circuit.  [2003-1-14 11:34:25]
[问:swn100] 1,索要《数字电位器》有关资料。2,《数字电位器》是不是很成熟的产品?如果购买,是不是可以得到很好的服务。3,《数字电位器》。他有多少型号,在那里可以看到更多的《数字电位器》。北京那里有,数字电位器》它的最大承电流能做到多大。 
[答:Way ne_zhou] You can send email to china.support@analog.com asking for materials. Digital potentiometer is product in mature, we can offer good services on our products.The biggest current can be 5 mA, but by adding outside FET, you can greatly improve the current limit, as slide 15 of the seminar.  [2003-1-14 11:34:58]
[问:lif71] 我刚才问的是:我需要3.3V,3通道,I2c,2美金/片。你告诉我AD5236,但我发现它不支持3.3V,且无参考价? 
[答:Char les_Lee] You can try AD5263 or ADN2860.  [2003-1-14 11:35:26]
[问:lu0049] 数字电位的稳定性和可靠性,在哪些方面不能代替传统的电位器 
[答:Eagle _Zhang] 1、ESD超4000V、高电压大电流以及极低价格时不可替代传统的电位器。2、在其应用范围内,数字电位器的稳定性和可靠性 精度 自动化程度等优于传统的电位器  [2003-1-14 11:35:44]
[问:dnmao yong] 数字电位器的调节方法是并行还是串行写入数据 
[答:Char les_Lee] Serial. SPI or I2C.  [2003-1-14 11:36:17]
[问:xkw1cn@ yahoo.com.cn] 当数字电位器用作半数字乘法器时发现噪音很大,请问这样用是否合适,如何改进,谢谢 
[答:Eric_liu] 因为数字电位器的带宽有限(小于1MHz),你必须考虑你的信号带宽。并且数字电位器本身的噪声较大。你可以考虑使用其他的方法实现,如AD834/835。  [2003-1-14 11:36:24]
[问:zihao942 75@sina.com] 在电路设计时,怎样考虑干扰的防止?
[答:Liao_ Wen_Shuai] Use the proper grounding and power supply technology as other circuits.  [2003-1-14 11:36:37]
[问:bslk5] 既然键控电位器在极值时不再发生变化,那么要继续调整时就必须反方向调整了,是不是? 
[答:Alan_Li] It depends how your controller detects the feedback signal and control the pot.  [2003-1-14 11:36:42]
[问:ljp] 当数字电位计和比较器配合使用时,比较器的滞后性能对它有何影响?如何解决? 
[答:Liao_ Wen_Shuai] The comparator won"t influence the digi-POT in the circuit.  [2003-1-14 11:38:37]
[问:zihao 94275] 请问数字电位计的输出精度是多大,对外界干扰有何要求,在制作电路时,应注意什么问题? 
[答:Way ne_zhou] At present 1025 resolution is maximum. The design request is just like normal part, you can refer to below materials: http://www.analog.com/technology/ amplifiersLinear/training/sensorSignal.html  [2003-1-14 11:39:11]
[问:czccsx] 数字电位器用于模拟量采样在抗干扰方面是否更好 
[答:Eagle _Zhang] 对低频采样,你可以用数字电位器构成可变带宽低通滤波器, 对不同信号用不同带宽,可以提高信噪比。  [2003-1-14 11:40:28]
[问:carl88 _98Y8Y] 数字式的电位计是否需要经常做偏移值的校正? 
[答:Peter_Kh] 0.25% after 1000 hours  [2003-1-14 11:41:35]
[问:lddqzj] 数字电位计的细度与传统的电位器相比有什么优势?数字电位计在价格方面与传统的电位器相比有多大的差别?数字电位计在温度特性方面与传统的电位器相比有什么优势?数字电位计在功耗上与传统的电位器相比有什么区别? 
[答: Alan_Li] Slide 3 covers all the benefitsDigital pot is not for all applications. Digital pot may cost 2-3 times more than mechanical pot. However, if you include labor and other cost variables, digital pot solution may be more cost effective.Best digit pots are 35ppm/C, much better than mechanical pots.Depends on parts and excluding the load dissipation, the chip itself consumes approx 100uW to 10mW power.  [2003-1-14 11:42:03]
[问:wt2756] 数字电位器对频率的响应敏感吗?它使用有没有频率范围的要求呢?谢谢! 
[答:Way ne_zhou] It"s depending on the resolution as well. For example, AD5273 can have 6 MHz bandwidth, but for those with lower resolution you can have better bandwidth. Also it"s code-dependent: lower code means higher bandwidth.  [2003-1-14 11:42:22]
[问:guocan] 数字电位器可以用于精密工业控制吗? 
[答:Eagle _Zhang] 可以,尤其是1024 级 (如AD5231,AD5235/6).  [2003-1-14 11:44:24]
[问:刘成勇] 请解释数字电位器的漂移情况 
[答: Peter_Kh] The main cause of drift is temperature varation due to the temperature dependance of the pn junctions contained in the active devices.  [2003-1-14 11:44:29]
[问:ljp] 影响数字电位计的精度有那些因素?在使用时要注意什么问题? 
[答: Alan_Li] wiper resistance is one of the sources of error. Stay away from using low value codes if possible.Tolerance is another error source which is 25-30%, see slide 13 for improvement for certain application. You may also choose high resolution parts to compensate the inaccuracy.  [2003-1-14 11:44:40]
[问:powerpro] 数字电位器可不可以实现128级以上。 
[答:Liao_ Wen_Shuai] The most precise is 1024. So there is no problem to implement it. AD5241, AD5235, and so on.  [2003-1-14 11:46:02]
[问:xiao ren0533] 请问现在最高等级的数字电位计控制精度可以达到多少? 
[答:Char les_Lee] 10 bits. But with extra digital POTs, it can up to higher resolution.  [2003-1-14 11:47:08]
[问:lddqzj] 就是说如果是无存储器的数字电位器在上电时它的阻值分配是不确定了了? 
[答: Peter_Kh] The value at power up depends on the device.  Most of the newer devices power up at midscale.  [2003-1-14 11:47:13]
[问:louyun] 数字电位器在各仪表用于调整参数时,需考虑相互之间的电隔离吗?如用于变频器等调速时,可当作模拟电位器用吗?谢谢! 
[答:Way ne_zhou] No need to consider the electronic isolation unles you system has special request. It can be same as analog potentiometer application.  [2003-1-14 11:47:24]
[问:louyun] 目前数字电位器的最小体积多大?有贴片式的吗?谢谢! 
[答:Alan_Li] Smallest availbale is SOT23 8 leads, AD5273, 6-bit, one time programmable, eval board is available.We will release SC70-6 in 6 months. Please checkback with us at digital.pots@analog.com  [2003-1-14 11:47:44]
[问: laowu_z] 如何应付电子电位器在使用过程中的跑飞现象? 
[答:Liao_ Wen_Shuai] Consider the EMI in the design, and reset it when there is problem. Or use OTP digi-POT in your system.  [2003-1-14 11:48:01]
[问:JakieW] Can I measure the resistance by multi-meter directly? 
[答: Peter_Kh] Yes...that is possible.  However, you must make sure that the device is powered up when taking the measurement.  [2003-1-14 11:48:12]
[问: liuyongtao] 现在的显示器使用的调节是否属于数字电位器,例如调节对比度、亮度等的
[答:Char les_Lee] As I know, it used the mult-channels 8 bits DACs or the DACs integrated into the MCU to doing the CRT contrast/Brightness, position ..ectc control.  [2003-1-14 11:49:07]
[问:yan-ying] 请问:数字电位器的种类有哪些,不同种类的数字电位器对其阻值变化的控制方式s是怎样的? 
[答:Liao_Wen_Shuai] There are three control methods: manual, I2C interface and SPI interface. There are two materials used in the resistance: poly silicon and thin film.You can refer to page 9, 18, 19, 20 for reference.  [2003-1-14 11:51:32]
[问:liuAM _7YP50] 数字电位器用于专业音响音量调节好象不多,是何原因? 
[答:Char les_Lee] The noise issue. Because the signal swing is about 2.6Vp-p normally and during very low signal level that could cause the noise issue gets worst.  [2003-1-14 11:52:36]
[问:Guyonglie] 请介绍AD5263 应用须知.            Guyonglie.  
[答:Liao_ Wen_Shuai] Just send mail to china.support@analog.com for details. Or call 800 810 1742. We will be glad to help you.  [2003-1-14 11:53:33]
[问:洋洋] 怎样可以控制零点漂移 
[答:Alan_Li] The absolute resistance drift is about 0.25% in 1000hrs under 125C burn in.However, if you application uses the digit pot as "3-terminal voltage divider" mode (slide 7) with a buffer as output, then RWA and RWB drifts are in ratio and cancel each other. The drift is minimum, 5ppm is not uncommon.  [2003-1-14 11:53:59]
[问:garon] 数字电位计耐高温吗? 
[答:Char les_Lee] Some can up to 105 degree C.  [2003-1-14 11:55:08]
[问: alexking] 数字电位器的误差以及转换精度? 
[答: Peter_Kh] The resistance tolerance is 30%.  The highest conversion accuracy we offer is 10bit(1024 step).  However, there are certain tricks we have that enable up to 20bits of resolution.  For more information on this technique, please email...digital.pots@analog.com  [2003-1-14 11:55:54]
[问:guang quan] 数字电位器是否可用于无线Mouse? 
[答:Alan_Li] I have not seen this application yet, please contact us at digital.pots@analog.com and I would like to discuss more.  [2003-1-14 11:56:09]
[问:swn100] 请问,《数字电位器》它的最大承电流能做到多大。 
[答:Char les_Lee] 5 mA for a single digital POTs. But you can add MOSFET to inrease the current.  [2003-1-14 11:57:17]
[问:jxccliu] 有数字电位计的典型应用的原理图吗?例如用在LCD的亮度和对比度方面。谢谢! 
[答:Eric_liu] We have many typical application circuit.Pls ref. to this seminar files.Digital potentiometer can use at LCD as same as analog potentiometer.  [2003-1-14 11:57:48]
[问:nui100] 数字电位器如何进行编程控制? 
[答:Way ne_zhou] You can use MCU or DSP to control it via SPI or I2C interface, or manual control by "up/down" clock" as AD5220.  [2003-1-14 11:58:00]
[问:刘成勇] 数字电位器在高频(70MHz)信号下的工作情况 
[答:Char les_Lee] No. It just can up to 6MHz and maybe 10MHz if the resolution is not that high.  [2003-1-14 11:58:32]
[问:zihao942 75@sina.com] 数字电位器失效的标准是什么?
[答:Alan_Li] All digit pots are 100% DC parameters tested before shipping. The failure rate is very small but I don"t have a ppm number to quantify it. Most of the failures were also found to be applications related.  [2003-1-14 11:58:54]
[问: kavin_shaw@ yahoo.com.cn] AD的数字电位器相对于其它竞争者的同类产品有何优势? 
[答:Way ne_zhou] Higher resolution, higher operating voltage as +-15V.  [2003-1-14 11:59:09]
[问:dnmao yong] 环境温度的改变对数字电位器的影响有多大 
[答:Eagle _Zhang] 对低温漂移的数字电位器(如ADN2850、ADN2860)的温漂小于30ppm/度, 工作范围 -40°C to +85°C,环境温度的改变对数字电位器的影响很小。   [2003-1-14 11:59:11]
[问:gxg] 为增加分辨精度,用多个数字电位器通过中间接头串联使用,其结果能否保证整体的线性性能? 
[答:Liao_ Wen_Shuai] You can do like this. But the linearity cannot be ensured because of the resistance of the wiper. We recommend you use our high resolution digi-POT.  [2003-1-14 11:59:17]
[问:ser] 數字電位器與傳統電位器的電路設計成本價差大概為多少?對於微型化電路設計的幫助為何? 
[答:Liao_ Wen_Shuai] Normally, digi-POT is expensive than mechanical one. But from the system point of view, it will be cheaper. Also, it can be smaller. For example, we have LCSP package.  [2003-1-14 12:01:35]
[问:lddqzj] 滑片电阻的意思是总阻值么?最小的总阻值是50欧姆对么? 
[答:Way ne_zhou] It"s only the wiper resistence, excluding the resistence of POT itself. 50 ohm is approximately the minimum value of it.  [2003-1-14 12:01:37]
[问:wy56] 多通道数字电位器的隔离度,目前可以达到多少dB?市场价格近期有可能大幅度降低吗? 
[答:Char les_Lee] It is about -75dB@10KHz. If you like to use it and have any price issues, please contact our local office.  [2003-1-14 12:02:28]
[问:张亚雄] 1、可否将数字电位器理解为是一种可对其电阻值进行控制的数字控制器件,而这种电阻值的控制是通过数字方式实现的?或者说可以通过编程方式获得?还是它仅仅是一个对电位变化进行接受的器件?而这种电位变化可以转化为数字量?2、请回答其控制精度是多少?多谢!张亚雄2003年1月10日 
[答:Eric_liu] 1.数字电位器可以理解为一种可对其电阻值进行控制的数字控制器件,而这种电阻值的控制是通过数字方式实现的或者说可以通过编程方式实现(spi/iic interface)。2.ADI have 33,64,128,256,512,1024 postion resolutions digital potentiometer.  [2003-1-14 12:04:26]
[问:zihao942 75@sina.com] 数字电位器在航天环境下可以使用吗?
[答:Char les_Lee] Some of the B grade part can operate from -40 degree C up to +105 degree C. We don"t have the military/space grade part for the digital POTs.  [2003-1-14 12:05:18]
[问:lddqzj] 请问:由于元器件的可靠性是由元器件的工艺和复杂程度决定的,那么高细度的数字电位器是否温度特性和抗干扰性能会比低细度的要差一些? 
[答:Liao_ Wen_Shuai] In fact the temp coef. is code dependant, so the temp coef. is decided by the material, code and connection usage. So it has no relationship with the resolution.  [2003-1-14 12:06:03]
[问:hugoshiu] 請問公司有IC 應用電路 光碟可贈送嗎? 
[答:Eric_liu] Yes.We can provie you short form,CD,samples.More information can find at www.analog.com or contact local office.  [2003-1-14 12:06:49]
[问:db1 x2y3z] ADI公司有没有数字电位器的实际应用电路可供参考? 
[答:Way ne_zhou] Please attend next seminar on applications of POT, we"re planning it in about May. You can get notice when we have fixed schedule. Also you can send email to china.support@analog.com, giving your request, then we can give relative materials to you.  [2003-1-14 12:07:03]
[问:louyun] 数字电位器的耐压值可达到多少?谢谢! 
[答:Char les_Lee] 30V maximum.  [2003-1-14 12:08:05]
[问:snow chang] 请介绍数字电位器在A/D转换器中的应用 
[答:Alan_Li] Several apps:It can work with ADC in contol loop application where ADC samples signal, processed through controller, and digit pot controls further action.It can also be used as front end PGA programmable gain amp to maximize the dynamic range.Digit pot can be considered as DAC if adding a buffer at the output.  [2003-1-14 12:08:47]
[问:WangF] 1。请提供数字电位器的精度与价格之间的列表。2。请提供它们的抗噪声特性3。请提供它们的频率特性 
[答:Eagle _Zhang] 1、数字电位器精度越高,价格越高,请与代理商联系报价事宜。2、可以用一个1uF电容加在抽头端,减小噪声。3、 频率特性与码有关。  [2003-1-14 12:08:47]
[问:lddqzj] 您建议使用OTP产品来作为防止使用过程跑飞的方法,是不是说其他的数字电位器产品在这方面还需要提高? 
[答:Liao_ Wen_Shuai] I just considering the fly away because of the interference. From other factors, there is no difference.  [2003-1-14 12:09:02]
[问:jxgao827] 请问专家:数字电位器的功耗大小如何划分?价格是多少?(零售) 
[答:Peter_Kh] The amount of power dissipation is dependant on the switch sizes.  Some of our newer lower resolution parts offer power consumption on the order of 5uA such as the AD5273.  [2003-1-14 12:10:38]
[问:lfj36@ sohu.com] 请问普通数字电位计在集成电路检测中有哪些局限性?应如何处理? 
[答:Liao_ Wen_Shuai] The digi-POT will bring in noise to the ATE. To deal with this, you can use high resolution DAC in the system.  [2003-1-14 12:10:44]
[问:lddqzj] 数字电位器是否有电压或功率限制? 
[答:Char les_Lee] ADI digital POTs can work up to 30V. The maximum current is 1mA.  [2003-1-14 12:11:20]
[问: kevin-yin @163.com] 为什么没有3.3v供电呢 
[答:Alan_Li] Sorry if datasheets are not clear but almost all digital pots can be operated from 2.7V to 5V. Even high voltage 15V pots can be operated at 3.3V.  [2003-1-14 12:11:35]
[问:TI] 请问数字电位器可以承受多大电流? 
[答:Char les_Lee] 1 mA.  [2003-1-14 12:12:24]
[问:potter] 数字电位计的稳定性(受温度、噪声的影响大小)如何?相对于可调电位计有哪些突出的优点? 
[答:Way ne_zhou] ADI offer good stability of POT chips. Compared to Rheostat, digital POT is more flexible, with higher resolution, no mechnical wear out, insensitive to vibration, small size, fast adjustment, and some else.  [2003-1-14 12:12:54]
[问:db1 x2y3z] 通常数字电位计应用最广的是哪一方面? 
[答:Liao_ Wen_Shuai] Digi-POT can be used in a lot of fields. You can find it in page 6 of the presentation.  [2003-1-14 12:12:55]
[问:louyun] 影响数字电位器的精度如与数字电位器内开关的电阻有关,是不是分辨率越高数字电位器的精度精度越差?如何避免? 
[答:Eagle _Zhang] 这还与标称电阻有关。 如果相同标称电阻的数字电位器,分辨率高(1024级)的在小电阻时比分辨率低(64级)相对误差会大,因为数字电位器内开关的电阻占的比例大。  [2003-1-14 12:13:37]
[问:luchang jun] ADI公司是否能提供500欧的数字电位器 
[答:Liao_ Wen_Shuai] No, we don"t have the digi-POT has the restance of 500 Ohm. But the AD5273 has the resistance of 1KOhm.  [2003-1-14 12:15:19]
[问:angelic] 我用过数字电位器DS1267-50,是50千欧姆的,每变化一位数字量,电阻变化近200欧姆,有没有,我查了一些资料,最小也是10千欧姆的,有没有更小的,还想请教他能承受多大电流 
[答:Alan_Li] Almost all of ADI pots have 10kohm version.Few pots such as AD5273, 8400, 8402, 8403 offer 1kohm version.Digit pots handle 5mA. For higher current, use pot to control the N-Ch MOSFET gate to get lower resistance but it is for limited applications, you may send email to digital.pots@analog.com and we will have more tips for you.  [2003-1-14 12:15:48]
[问:wt2756] 数字电位器挂在I2C总线上时,对器件的数量有没有要求呢? 
[答:Char les_Lee] 127 devices is the maximum I2C can handle. But if you used same parts numbers of the digitla POTs on the I2C bus. It just can up to 4 same devices.  [2003-1-14 12:16:43]
[问: anthonyz] 贵公司的EEPOT比起XICOR公司的有何优缺点? 
[答:Way ne_zhou] You can have wide range selection from ADI part, from the point of resolution, operating voltage, tempco, resistence.  [2003-1-14 12:16:45]
[问: Tony Chai] 数字电位器的可靠性有没有一个参考值? 
[答:Alan_Li] please send me email at digital.pots@analog.com and I will give you the ppm number.  [2003-1-14 12:16:45]
[问:JJ63901] 请问数字电位计有哪些成功的应用案例?谢谢! 
[答:Liao_ Wen_Shuai] We have used it in the base station, PDA, laser diode, mobile phone, industry and PC successfully. Also, it can be used in more fields.  [2003-1-14 12:17:31]
[问:laowu_z] 有否在片上实现数字端口和模拟端口的光电隔离的数字电位器? 
[答:Eagle _Zhang] 暂时没有, 可以用外部光耦隔离。  [2003-1-14 12:17:39]
[问:bslk5] 请问adi公司有没有键控的数字电位器,有没有可循环调整的数字电位器,如有请提供具体型号. 
[答:Way ne_zhou] Please refer to AD5220, AD5222.  [2003-1-14 12:18:36]
[问:laowu_z] 为提高电子电位器的分辨率,可否将多个电子电位器串联使用,如果可以,应该注意那些事项? 
[答:Eagle _Zhang] Please refer to previous answer. Or contact ADI local office is you are not clear. Thanks.  [2003-1-14 12:18:48]
[问:laowu_z] 目前的电子电位器模拟端口的最大功率是多大? 
[答: Peter_Kh] The maximum power dissipation would occur at the maximum current which is specified at 5mA.  Therefore the max power that the part can dissipate is about 25mW.  [2003-1-14 12:19:01]
[问:hjldfp] 请问:    数字电位器的转换精度是多少?转换时间?    能不能将电阻或将4~20mA电流转换为数字量? 
[答:Liao_ Wen_Shuai] The most precise is 1024 steps. The conversion time is in the micro-seconds.We cannot transfer it into digital signal.  [2003-1-14 12:22:19]
[问:gxg] 贵公司何时能有12bit的高精度数字电位器,它的价格怎样? 
[答:Alan_Li] We do not see the market yet but please discuss with me at digital.pots@analog.com further if there is good potential.Meantime, please read AD5233 datasheet Figure 29http://www.analog.com/UploadedFiles/ Datasheets/288936787AD5233_0.pdf or app note figure 6 inhttp://www.analog.com/UploadedFiles/ Application_Notes/20666174AN582.PDF  [2003-1-14 12:22:23]
[问:lddqzj] 1。数字电位器可以承受的最低工作温度是多少?2。ADI的15V和30V的数字电位器是否和5V的是不同型号或者有不同的尾标?价格是否差异很大? 
[答:Eric_liu] 1.-40 to 85 Celsius degree. some B grade parts can work -40 to 105 celsius degree.2.It is nothing with appendix. for exampl,AD7376 can be use at +5 V to +30 V Single Supply Operation or +-5 V to +-15 V Dual Supply Operation. Pls contact our distributor for exactly price.  [2003-1-14 12:27:18]
[问:TI] 将数字电位器放在程控放大电路中,做为负反馈阻值,效果如何;请介绍一下数字电位器常用的封装形式。 
[答:Alan_Li] It works good for gain of 10 or lower, higher gain requires 2nd stage. Sometimes it is better to configure like slide 38 such that digit pot is used for attentuator, and then gain it up with fixed gain but noise will be gained up.  [2003-1-14 12:27:29]
[问:hzzwd] 请问:数字电位器的精度是否可以做到1%? 
[答:Liao_ Wen_Shuai] Nobody can provide this kind of digi-POT. You can use high resolution DAC in the circuit.  [2003-1-14 12:27:50]
[问:cqu zhutao] 你好!我想询问一下有关数字电位器的调节精度和可靠性问题,因为在我们的设计中需要比较高的调节精度和较高的可靠性!谢谢 
[答:Alan_Li] If it"s an open loop application, there is not much solution to improve the accuracy. If it"s close loop design, choose higher resolution pots to compensate the inaccuracy. Please send me email at digital.pots@analog.com to discuss further. [2003-1-14 12:30:31]
[问:swn100] 数字电位器,它的综合性能是目前最好的吗?请问它未来的应用,以及性价会不会占领最大市场? 
[答:Alan_Li] Depends, it can replace some of the low resolution DAC converter applications such 10-bits below. However, it does not offer the precision as DAC.Digital Pot is very vesatile to configure variety of ckts also. See 2nd half presentation as well as Part II netseminar.  [2003-1-14 12:32:41]
[问:lushenkai] 如和在音频电路上使用数字电位器?数字电位器比模拟电位器相比有那些优缺点?可否提供一些应用实例? 
[答:Eric_liu] Pls. ref. to our seminar files. for examle, digital potentiometer have samll package,high accurare,wide temperature range, programable controll etc.  [2003-1-14 12:32:48]
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