• RE: AD719x reference buffer amplifier?

    Hi Oliver,

         When using the ADR431 as reference to the AD7190, it is okay not to use buffer as the ADR431 is able to drive the AD7190 as the average current in the reference is about 7uA/V. Now when not using the ADR431, it can be consider to use buffer…

  • AD使用的高精度基准源问题 ADR431

    请教ADI的工程师们,我们现在在用24位的AD做数据采集,原则上,这种24位的AD应该配一个高精度的基准源来做参考电压,比如说ADR431,国内基本上买不到,找替代品的话,价格几十块,或者上百,还不容易买到。比用一片AD价格还高,从控制成本的角度说,不太让领导接受。

    请教ADI工程师们,那如果我能找到超高精度的电阻,那能不能用电阻分压代替基准源呢,比如说

    ADR431                                精度+/-0.04%  ,温度系数:1,噪声3.5

    高精密电阻                          精度+/-0.02%,温度系数: 5,电源的噪声20,

    那可不可以使用这种高精密电阻来弥补一下ADR431的作用呢…

  • RE: 专家好,在ADC转化中需要正负2.5的基准电压源!

    您好!

    使用ADR431产生也是可以的。就和数据手册中19页图38中电路实现相同,只是将ADR435换成ADR431输出+2.5V电压,经过反相电路后产生-2.5V。两种方案都是可以的。

  • RE: AD7966 external reference input

    Hi pedicularis,

    Yes, the AD7699 REFIN input min/max range is 0.5V to (VDD-0.2)V using an external reference, so the reference buffer can still be used with the 4.5V reference such as ADR431.

    Regards,

    Maithil

  • RE: wrong conversion with AD7691

    Hi Jonathan,

    we try to connect the ADR431 directly to Ref pin but nothing change...

    Could be that the AD7691 doesn't receive the start of convertion and when the fpga ask for reading it gives the same code of the last conversion? But this is strange…

  • RE: AD7655 return's 0xffff

    Hi Braddis,

       The AD7655 typical Vref at 2.5V, the 0xFFFF full scale output should be when analog input voltage is 5V.  May I ask what reference are you using? The AD7655 datasheet recommends voltage reference like AD780, ADR421 and ADR431. These references…

  • ADR431BRMZ, error in package type of datasheet order guide

    I notice for ADR431BRMZ that the datasheet says the package for this part
    should be an 8-pin SOIC_N, but the website says it’s an 8-pin MSOP.

     

    There is a mistake in the datasheet order guide for ADR431BRMZ-R7.

    The part number ADR431 B RM Z -…

  • RE: AD7190 Voltage Reference

    Hi Johnny,

    Thank you very much for the response.  In some applications, I won't be using an ADR431 type reference, so for the input impedance, I am interested in the frequency dependent nature.  The data sheet mentions that the input impedance is dynamic…

  • RE: AD680 adding tow capacitor

    Hi, Osamu.

    According to the applications engineer of AD680, ADI does not guarantee the performance of AD680 when a capacitor is connected between the TEMP pin and ground because AD680 was not designed for that purpose.

    As alternative, you may try the…

  • RE: Transient behavior on first samples of AD7980

    Hi Percy,

    From the AD7980 data sheet:

    When REF is driven by a very low impedance source, for example, a reference buffer using the AD8031 or the ADA4805-1, a ceramic chip capacitor is appropriate for optimum performance. If an unbuffered reference…