用运放搭建零阻电流计,用来测量微安级电流,用AD8638是否合适呢?或者是否还有比它更适合的芯片?
Q.
I am looking for an op amp to signal condition a low frequency (<100Hz) temperature sensor. I need a high precision amplifier with good offset voltage and drift. What are the appropriate amplifiers that you recommend?
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Hi Jac,
AD8638 is the Op amp we recommend using. The resistor values have been updated please see attached document for the latest circuit.
Regards,
Jim B
Hi Laxman,
If you take a closer look, the first amplifier on that configuration has a gain of 1000. This would greatly amplify any DC errors on the inputs of the amplifier, including the low offset voltage of the AD8638 from 3uV to almost 3mV. The 10uF…
最近在使用ADI官方的Spice模型进行仿真时,发现有一些元器件的官方Spice模型在LTSpice中导出仿真文件时,元件符号是一个矩形,引脚上也没有对应的引脚序号和名称,如:“AD8638”。
这在调用仿真文件时需要打开模型文件对引脚功能进行确认,很不方便。
现在我希望在导出仿真文件后可以对其原理图符号和引脚名称进行编辑,比如像 “AD711” 这样。
需要怎么做?
Hi Rainier
Thank you for your suggestion.
another question about AD5791 ( 20 bit DAC ) & AD5541A ( 16 bit DAC )
Which spec is concerned about replace the uni-gain buffer ( AD8638 or AD8639 ) to AD8675 ?
Since the Input offset voltage for AD8638 is 3…
Hi Emman,
It is functioning well but as temperature changes the drift of output current is also large. So i was looking for an IC which had low offset voltage and drift. Then i came across AD8638, AD4522-2 etc. One doubt which i have is that, in the…
最开始恒流源电路用的是op177,这个倒是很稳,但是这个不是个轨到轨输出的。
然后换了个轨到轨的AD820,板子上一共16路恒流源3V基准(图里3k实际是)1.2k电阻,正常电流应该是2.5mA,但是实际输出的啥值都有2.444,2.511······
又换成AD8638,正常这个应该更好,失调电压更低。但是实际才2.1mA输出,郁闷····
换回op177…