MOS operational amplifier (opamp)

• In many cases the most important building block of analogue circuits
  
• Its performance usually limits the the high-frequency application and
  the dynamic range of the overall circuit

Symbol for ideal opamp:

Equivalent circuit:

Basic characteristics of an ideal opamp:

• Voltage-controlled voltage source with
  
• Infinite voltage gain
  
• Zero input admittance
  
• Zero output impedance
  
• No frequency and temperature dependence, distortion, noise