• AD8626 voltage noise issue

    Hi Experts,

    I am testing a circuit that TIA pre-amp used AD8626.

    I used Fig45 of spec page15 topology, and 2 OP are used.

    I used same opto-diodes in the -INA and -INB inputs.

    As I thought, the voltage noise of 2 OP should be same.

    But the test shown…

  • RE: What other Jfet amplifier can replace ADA4610? I cannot find it on supplier sites anymore. Thank you!

    Hi Matei, 

    Do you have a specific step size that you need to work with? The AD8626 seems to have lower slew rate and bandwidth compared to the ADA4610. What is your input and expected output?

    Thanks, 

    Kris

  • RE: pH计(酸度计)和电导率仪那些事

    PH计设计的主要考虑因素有: 稳定性、分辨率、低功耗。结合上面提供的咱们ADI的解决方案,看看如何满足这些需求:

    多数pH计提供3.位的分辨率,这意味着16位Σ-Δ ADC即足够。某些实验室pH计的分辨率可能高达5.位,此时应当使用AD7793等。24位Σ-Δ ADC和低闪烁噪声放大器ADA4505-2/AD8626。

    仪器仪表的一大趋势是小型化和便携化,这对低功耗设计带来挑战。上表中每个类别下的产品中都有低功耗器件。例如:ADA4505-2/AD8626、ADR291、AD7792/3、ADuCM361…

  • RE: How to meet high input resistance and input bias current return requirements?

    Hi Emmann,

    I want to measure small DC signal variation on the soil surface. Small

    signal means as low as 10 microvolts. Two special electrodes are

    touching/contacting the soil and the signal occures between them. The

    electrodes are connected to the…

  • RE: hi.in ADI Water Analysis Solution for pH Meters.pdf there is a block in the name of programmable ac current in conductivity meter . i can not understand why there is not a single current source for that

    thanks alot it is absolutely right . i have used ad8626 opamp in my circuit and i got wrong current from +vref and when use -vref.the other task i want to have 1ua current with this circuit . i wanna know your opinion about using r3 about 2 Mohm is this…

  • RE: AD8627输出震荡

    看不清时间轴,是50Hz工频的?

    正相输入,设计是想做跟随,还是放大的?

    Follower是最容易振荡的,要选用标有“unity gain stable”的OPA的,AD8626 datasheet第一页写了它是的。

    另外,电源供电引脚,有用电解+MLCC的组合了的?

  • RE: Amplifying 40 - 80 uV with DC bias of at least 200 mV.

    Hi Fridrik,

    I am thinking of limiting the gain of the first stage instrumentation amplifier to probably less than 10V/V (enough not to saturate the part by the dc offset)  and followed by high pass or a band pass filter stage to  removes dc effects and t…

  • ad822: Phase reversal (1)

    A customer is reporting a behavior of the AD822 as follows:
    If an input gets a voltage level that is above the Vdd, the output is going low
    instead of staying at Vdd potential.

    ° Would it be possible to get some infos on the background…
  • RE: 有奖创想,一起来做环境监测“创客”(获奖名单已公布)

    土壤酸碱度测量仪


          随着生产和生活越来越工业化、现代化,环境对我们人类的影响问题也变得很突出!

    大家认识到加大力度保护空气、水、土地、森林等宝贵资源刻不容缓!


          民以食为天,粮食是宝贝,生产粮食的土地是宝中宝!现在的农业生产由于大量使用化肥和农药使得土壤的

    酸碱度偏高或偏低,部分改变了土壤的结构,不利于农作物的生长,导致了粮食和庄稼的减产。


         传统的PH测量采用化学试纸办法,效率低,测量误差较大;同类的电子产品稳定性不太好,精度不高,功耗大,功能单一。


         因此我想设计一款能测量土壤酸碱度的仪器…

  • ADI公司针对pH计和电导率仪的水分析解决方案

    ADI公司针对pH计和电导率仪的水分析解决方案

    应用简介

    本文将讨论水分析领域最常见的两种应用:pH计和电导率仪。
    pH衡量溶液的酸碱度。我们知道,大多数生物要求适当的pH水平以维持生命。pH的测量在许多领域至关重要,例如化学处理、纸浆和纸、食物、饮料、制药等等。
    电导率衡量溶液导电的程度,测量电导率是一种极其广泛且有用的质量控制方法。监测水的纯度、控制饮用水和过程用水的质量、估算溶液中离子的总数等,全都可以通过电导率测量来实现。一般而言…