Page 852 - Mechanical Engineers' Handbook (Volume 2)

2 Operational Amplifiers 843

R
V out ƒ
1 (62)
R
V in
Gain 1
and V have the same sign so the amplifier is noninverting. This circuit is often
Here V out in
used as a buffer to ‘‘isolate’’ one portion of a circuit from another.

Type Schematic Input/Output Equation

R

R 1
Summer V out = − ( 1 VV + 2 )

– +
V 1 V 2 R 2 +

R f
R 1
–
+ V out R f
Difference amplifier + V out = ( 2 V − 1 V )
V 1 R 2 R
+
– V 2 R F
–

R 1 t
=
x
t
V out () − V in () dx
Integrator + – RC ∫ 0
V in +
V out
–

R
in
Differentiator − RC  dV   = V out (t )
+ C –  dt 
V in +
V out
–
 R 
R 2 R 2 2 
V out = − V +  +1  V ref

1
R 1  R 
1
Gain and shift R 1
if R = R = R

amplifier – 1 2

V out R f
+ V out = ( 2 V − 1 V )
V ref R
Figure 29 Useful op amp circuits.