SUMMING AMPLIFIER

THIS PPT ABOUT SUMMING OF AMPLIFIER.

1. GOVERMETNT ENGINEERING COLLAGE, BHARUCH Sub :- BASIC ELECTRONICS Topic :-Summing Amplifier using OP-AMP Made by:-ASHISH MISHRA (150140111055)

2. Summing Amplifier It is possible to apply more than one input single to an inverting amplifier. This circuit will then add all these input signals to produce at the output. Such a circuit will then be called an adder or a summing amplifier.

3. Inverting adder The inverting summing amplifier configuration with three inputs V1, V2, and V3 Depending on the relation between the feedback resistor R F and the three input resistor R1, R2 and R3 we can use the same circuit shown in figure. V1, V2 and V3 are measured with respect to ground. R f is the feedback resistor connected between the output terminal and the inverting input terminal of OP-AMP. The non-inverting input terminal is connected is ground.

4. We now have an operational amplifier circuit that will amplify each individual input voltage and produce an output voltage signal that is proportional to the algebraic “SUM” of the three individual input voltages V 1 , V 2  and V 3 . We can also add more inputs if required as each individual input “see’s” their respective resistance,  Rin  as the only input impedance.

5. This is because the input signals are effectively isolated from each other by the “virtual earth” node at the inverting input of the op-amp. A direct voltage addition can also be obtained when all the resistances are of equal value and  Rƒ  is equal to  Rin . A   Scaling Summing Amplifier  can be made if the individual input resistors are “NOT” equal. Then the equation would have to be modified to:

6. Thank you