741 Op-Amp Circuit

1
741 Op-Amp Circuit

• Section 8.1 (Razavi)

2
Equivalent Circuit of an Op-Amp
Characteristics Negligible input current Large
input AC resistance Small AC output
resistanceLarge Voltage Gain
3
Op-Amp as an Amplifier
(non-inverting input)
(inverting input)
Op-Amp is a circuit that amplifies the
difference between the inputs.
4
ST UA741CN Op-Amp
5
ST UA741 CN Schematic
6
Spec Sheet for ST UA741 CN
7
UA741 CN Specs (Cont.)
8
Topics

• Non-Inverting Amplifier
• Inverting Amplifier
• Integrator
• Differentiator

9
Non-Inverting Amplifier (Ideal)
(Assumption Ao is infinite)
10
Inverting Amplifier
Input impedance R2
Trade off Input impedance versus voltage gain.
11
Virtual Ground Versus An Ordinary Ground
Node X is a virtual ground, but not an ordinary
ground. If X were an ordinary ground, current
from Vin would be diverted from R1since R1
represents a path of high impedance.
12
Differential Amplifier
If R1R2 and RfRg, then Vout/(V2-V1)(Rf/R1)
13
Instrumentation Amplifier