• AD7745

    Hello

    Our customer will use  AD7745 as  as attachment. 

    They would like to measure   Cx-Cy at one case and   Cy only at other case.

    Can they connect Cin1- and Cin2 + ?

    ( Is there any  inteference between Cin1- channel and Cin2+ channel ?)

    Please let me know…

  • Level Sensor by using AD7745

    Dear All,

    Currently, I am working on level sensing project by using AD7745. The liquid capacitive range is 3~300pF. However, AD7745 has a range of 0-4pF. Do you have any idea? how could i extend the range of AD7745 to be 3-300pF?

    Thanks,

    Hossam

  • AD7745 3-wire RTD measurement

    Hi,

    We are currently working on a measurement system with a capacitive sensor and an RTD. For the measurement of the capacitance, I am using AD7745 CDC . 

    How could we implement an RTD measurement system using the AD7745/46 CDC's ? Is there an reference…

  • RE: AD7747 - Liquid Level Measurement

    Hi Kumar,

    Your equation for Cin looks inline with that used in the evaluation software, it should be ok.  Cref is the internal reference capacitance. I have attached an application note that has some detail on this parameter (page 2) which should be true…

  • AD7745_there is no input protection circuit

    Are there some protection circuit in front of the AD7745 to limit the input
    voltage and current while not affecting the capacitance measurement.

     

    the AD7745 has no over voltage protection please refer to the absolute maximum
    ratings…
  • RE: Eliminating the cable capaciance

    Hello Baala,

    The AD7745 is only designed to measure a maximum of 17pF (CAPDAC) ±4.096 pF (Input Range); it does not seem suitable for your sensor, even without the cable.

    The AD7745 only measures the capacitance between the EXC and CIN pins, and you…

  • AD7745 External Excitation

    Hi,

    I have to measure the capacitance of three capacitive sensors which are placed together. AD7745 seems ideal for the application. But if I use 3 different excitation sources(one in each chip of AD7745),even if there is a small difference in the frequencies…

  • RE: 菜鸟求救:如何用AD7746进行测量金属平板电容

    测量范围为:11.5pF~23.5pF,已经超出AD7746的正常测量范围。通过降低7746的激励电压,可以提高待测电容的容值范围,见附件的方法,但注意这样做的损失是转换结果的精度会下降,如果容值范围变为+-100pF,则精度会损失6~7个Bit。

  • AD7745 with Multiplexer

    Hey Guys,

    i am working on development of a pressure sensor with a matrix-like arrangement of the electrodes.

    So i have columns and rows and would like to measure the floating capacities.

    The area consists of 25 measuring points and now i consider to…

  • AD7745 Resolution

    I have a couple of questions regarding AD7745's resolution:

    - can I sense a 5aF capacitance variation in a 1pF nominal capacitance with the 21 ENOB and still have the entire dynamic range (e.g. 350fF) available, assuming a 10Hz BW;

    - Is it possible…