本帖最后由 哪哒草 于 2015-4-8 10:42 编辑

dontium 发表于 2015-4-8 08:41
这是你的电路：













不知道我所标的引脚是否正确？？







芯片的内部电路：











3、4、5、6是调整的。





OFFSET VOLTAGE NULLINGThe offset voltages of both input stages and the comparatorhave been pretrimmed so that external trimming will only berequired in the most demanding applications. The offset adjustmentof the two input channels is accomplished by means of adifferential and common-mode scheme. This facilitates fineadjustment of system errors in switched gain applications. Withthe system input tied to 0 V, and a switching or carrier waveformapplied to the comparator, a low level square wave willappear at the output. The differential offset adjustment potentiometerscan be used to null the amplitude of this square wave(Pins 3 and 4). The common-mode offset adjustment can beused to zero the residual dc output voltage (Pins 5 and 6).These functions should be implemented using 10k trim potentiometerswith wipers connected directly to Pin 8 as shown inFigures 9a and 9b.



不知道它会不会影响呢？

标的没错。

我试了连接22k滑变，滑到头也没啥变化。

我把频率调小后，两路信号10倍频，是这样的波形，看着还凑合（下图）



但是如果频率都是1khz，幅值不一样，就变成这样的了（上图）