Operational Amplifier (Op amp)
An operational amplifier (op amp) is an electronic device consist of a large number i.e. twenty and above.
It has 3 terminals two input terminals and one output terminal.
The op amp can perform electronically mathematically of such as additional, subtraction, multiplication, differentiation, integration
Properties of an op- amp
i) It has got a very high voltage gain called the open loop gain which typically is 105 for dc and low frequency but decrease with frequency.
ii) It has a very high input resistance typically 10, it draw a minute current from the signal source.
iii) It has a very low output resistanceR0, typically 100Î.
Description
It has one output and two inputs and one non inverting (
and one inverting (-).
Its operation must convenient from a dual balanced power supply giving its equal +ve and –ve voltage (+Vs, or,-Vs)
Inverting amplifier
=
(
–
)
=
Some of the output goes back to the input .This red called the amplification from A0 to A
But
I1, = I2
Example
(i)Find the closed loop gain of the inverting amplifier
From
= -10
ii) Supposed the voltage gain is to be increased to 40 and the current of 
remains the same .What are the values of the resistors required to gain this
NON INVERTING AMPLIFIER
The fraction β fed back via Rf
LOGIC GATES (Non inverting)
+ 
