The earliest IC opamp OUTPUT stages were NPN emitter followers with NPN current sources or resistive pull-downs, as shown in Figure 1.6.
最初的集成运算放大器的输出级是NPN电流源的NPN放射追随器或通过电阻下拉,如图1.6所示。
2
There may be saturation in the differential circuit built with the operational amplifier (opamp), which causes that the relationship between input and output is not differential expression.