Please help me on this.... The following circuit is of an active rectifier..The inclusion of a diode here signifies a voltage follower for positive Vin voltages ....but for negative Vin diode is off hence the out voltage Vout is zero....and the output of the opamp goes into negative saturation (opamp sinks current for negative Vin cycle)...But here comes a certain slew rate limitation of this circuit...with high-speed signals.The op-amp cannot swing its output infinitely fast, the recovery from negative saturation takes some time, during which the output is incorrect... In order to deal with it and improved version of the circuit consisting of two diodes is employed as shown in figure 2.. The text says that "The improvement comes because the op-amp's output swings only two diode drops as the input signal passes through zero."... What does that means...?