Op-amp is in closed loop configuration when there is a connection either direct or via another network exist between the input and output terminals.We can control the gain of op-amp if we introduce a modification in the basic circuit.This modification involves a feedback ie the input signal is fed back to the input either direct or via another network. Different feedback configurations An op-amp that uses feedback is called a feedback amplifier.A feedback amplifier is sometimes referred to as a closed loop amplifier because the feedback forms a closed loop between the input and the output.A close loop amplifier can be represented by using two blocks one for op-amp and the other for a feedback circuit.These connections are classified according to whether the voltage or current is fed read more

If you enjoyed this post, make sure you subscribe to my RSS feed! Read more »

When connected in open-loop configuration,the op-amp functions as a high gain amplifier.These are three open loop op-amp configurations. Differential Amplifier Inverting Amplifier Non-Inverting Amplifier These configurations are classed according to the number of inputs used and the terminal to which the input is applied when a single input is used. Disadvantages of open loop configurations The open loop of the op-amp is very high.Therefore only the smaller signals having low frequency may be amplified accurately without distortion. Open loop Voltage gain of the op-amp is not a constant voltage gain varies with changes in temperature and power supply as well as mass production techniques.This makes op-amp unsuitable for many linear applications Bandwidth of most open loop op-amps is read more

If you enjoyed this post, make sure you subscribe to my RSS feed! Read more »