AMPLIFIERS NON-INVERTING AND INVERTING AMPLIFIERS

• The Open-loop gain called the Gain Bandwidth Product, or (GBP) can be very high and is a measure of how good an amplifier is.
• Very high GBP makes an operational amplifier circuit unstable as a micro volt input signal causes the output voltage to swing into saturation.
• By the use of a suitable feedback resistor, ( Rƒ ) the overall gain of the amplifier can be accurately controlled.

Differential and Summing Amplifiers

• By adding more input resistors to either the inverting or non-inverting inputs Voltage Adders or Summers can be made.
• Voltage follower op-amps can be added to the inputs of Differential amplifiers to produce high impedance Instrumentation amplifiers.
• The Differential Amplifier produces an output that is proportional to the difference between the 2 input voltages.

Differentiator and Integrator Operational Amplifier Circuits

• The Integrator Amplifier produces an output that is the mathematical operation of integration.
• The Differentiator Amplifier produces an output that is the mathematical operation of differentiation.
• Both the Integrator and Differentiator Amplifiers have a resistor and capacitor connected across the op-amp and are affected by its RC time constant.
• In their basic form, Differentiator Amplifiers suffer from instability and noise but additional components can be added to reduce the overall closed-loop gain.