Inverting Amplifier - Op-Amp Circuits
Input Impedance of this module is Ri as pin 2 is
at virtual ground, the opamp with feedback tries
to maintain pin 2 and 3 at same potential pin 3 is
at 0V hence pin 2 is at virtual ground. Clamping
diodes protect OpAmp, Rf + Ri is between 5kE and
1ME as an opamp may be able to drive around say
Notes delabs - Analog Basics 06
Current into node pin 2 = Vin/Ri if Vin is +ve it
raises potential at pin 2, in order to bring it to
0V the OpAmp sucks away the current by turning its
output negative the current leaving pin 2 node is
also Vin/Ri. Then Vout is given by Vin/Ri * Rf as
per V=IR ohms law. Most OpAmps output swings
around 1v less than VCC/VDD for full swing use
CA3130 this is a FET input OpAmp, and has low bias
currents in pico amps.
Programmable Gain Amplifier
This is used as a small signal amplifier. Used
after the buffer stage. Multiple stages
cascaded for higher gains. An Interactive
Tutorial with Simulated Meters and Potentiometers,
demonstrating how an Inverting Operational
Amplifier functions is far below.
Vout = Vin * (-1) * (Rf/Ri)
Interactive Tutorials using Virtual Electronic
Slide the Potentiometers just like you would operate
a Sliding Control. Drag the Knob on Pot to increase
or decrease the resistance. The Resistance is shown
is blue letters and dynamically alters value as you
slide the pot.
PID control using OpAmp
The mV Source is varied by just moving mouse pointer
over the two buttons, no clicking. This reduces
finger strain and also you have a long lasting
mouse. The mV buttons are special, the variation
picks up speed if you let the mouse pointer remain
on the button. This is Ramp-up and Ramp-down. This
enables you to set it faster with just two buttons.
Finally you have a DVM a Digital Volt Meter that
just Displays the Voltage at any Point, this readout
value has to be noted down.
Use the "iframe" part in this
Inverting Op-Amp xml code
Op-amp Varieties - Operational amplifiers are
very versatile electronic devices. This is a
sampling of the kinds of devices which can be
created with a single op-amp.
Operational Amplifier Circuits - We have
built voltage and current amplifiers using
transistors. Circuits of this kind with nice
properties (high gain and high input impedance, for
example), packaged as integrated circuits (ICs), are
called operational amplifiers or op amps.
More Opamp Simulations