Op Amp Gain Control. Two types of amplification are very easy to implement. Alternatively if r2 is given a value of zero the gain equals the open loop gain of the op amp.
The closed loop gain of the integrator will be r2 r1 just like a normal inverting amplifier. The gain can thus be made variable by replacing r1 with a pot and connecting its slider to the inverting terminal of the op amp as shown in the circuit in figure 4 in which the gain can be varied over the range x1 to x101 via rv2. Op amp integrator with dc gain control to avoid the saturation of the output voltage and to provide gain control a resistor with high value of resistance can be added in parallel with the feedback capacitor cf.
We know now that an operational amplifiers is a very high gain dc differential amplifier that uses one or more external feedback networks to control its response and characteristics.
The gain at digital 000 is unity or 1 and the gain at various stages are set by 4051. Precision attenuator with digital control delabs. We saw in the last tutorial that the open loop gain a vo of an operational amplifier can be very high as much as 1 000 000 120db or more. The gain can thus be made variable by replacing r1 with a pot and connecting its slider to the inverting terminal of the op amp as shown in the circuit in figure 4 in which the gain can be varied over the range x1 to x101 via rv2.
