• AD8622: macro model is for +/-15V supply only, Have you got a macro model for AD8622 for +/-2.5V supply voltage operation?

    Have you got a macro model for AD8622 for +/-2.5V supply voltage operation?
    For Vs=+/-5V it works fine but it doesn’t work with +/-2.5V. 

     

    Our SPICE models are usually created for the higher supply voltage of the op
    amp (mentioned in…
  • PSRR of AD8622

    On pages 3/4 of the data sheet, a minimum PSRR of 125 dB @ 25°C is specified,
    whereas in Figs. 29/32 the PSRR apparently settles to slightly above 100 dB
    below 10 Hz. Could you please explain the reason for this discrepancy?

     

    The specs table…

  • AD8622使用

    在使用ad8622 构成仪表放大的时候,当输入端悬空什么都不接的时候,输出端是电源电压,因为用这个仪表放大测量脑电信号,当接到人体的时候,因为第一级仪表放大只有10倍,脑电信号5-

    200uv,但是在输出端测的时候,有100mv,好像是有个直流偏置,幅值在100多mv上下变动

  • The AD8622 with ~10uF capacitive load

    I want to use the AD8622 at +/-5V to drive a 10uF capacitor. Will that cause a stability problem?

  • Can AD8221BR, AD8622 improve current design?

    We are redesigning a test board due to heating in a few LT1167 (LT1167ACS8) and LT1352 (LT1352CS8) devices. Due to lack of information on the specific devices that heat up, done LT Spice simulation for circuits, and have nearly narrowed down on the problem…

  • High value resistors in AD8622 differantial mode amplifier configuration

    I'm applying two sinusoidal signals to the inputs of a AD8622 which is configured in differantial amplifier mode. The applied signals swings from -1.65V to +1.65V @1KHz. The applied signals have a phase difference of 180 degrees. I'm using amplifier to…

  • 关于ad8622的使用问题

    在用ad8622构成三运放仪表放大电路中。如果输入端什么都不给,悬空的时候,输出是电源电压,还有就是,因为用来放大人体脑电信号,接到人头上,脑电放大仪表放大只有10倍,按理说只有mv最大,了,可是,用万用表,测量发现有一百多mv,类似于加了个直流偏置,导致后级放大没法用过高倍数放大脑电,

  • AD8622 spice model output current at zero input

    Hello,

    My test circuit is very simple: non inverter amp, gain 2, 500 ohms resistors .Input is 1uV(for test).I measured Vout ~-1mV .The input bias current was measured to be ~300p, but the output current  was ~1.2uA, so it is the reason to the -1mV output…

  • AD8622:双运放差分放大的问题

    图中是我用的放大电路,需要放大的电压信号是负载电阻两端的电压,其通过恒流源供电。

    ①单独测试前级放大电路时,第一级放大电路的放大倍数不对,理论值应该是49倍,结果测出来的是70多倍,有时候甚至到了130多倍。

    但是当所测试的负载电阻由电池供电时,也就是恒压供电时,测试的结果就变正确了。

    ②单独测试后级放大电路时,仪表放大器放大负载电阻的电压,无论恒压源还是恒流源供电测试结果正确,没有出现很夸张的错误数据。

    问题1: 这种两级放大电路结构到底对不对呢?

    问题2:为什么当由恒流源给负载供电时…