Differential Amplifier Circuit Diagram. It consists of two transistors q 1 and q 2 that have identical ideally characteristics. R1 and r2 are the input resistors rf is the feedback resistor and rl is the load resistor.
R1 and r2 are the input resistors rf is the feedback resistor and rl is the load resistor. They share common positive supply v cc common emitter resistor r e and common negative supply v ee. It consists of two transistors q 1 and q 2 that have identical ideally characteristics.
Figure 3 shows a block diagram used to represent a fully differential amplifier and its input and output voltage definitions.
In an ideal differential amplifier the output signal is proportional to the difference between the two input signals. Fig 2 i shows the basic circuit of a differential amplifier. There are two inputs i1 i2 and two outputs v1out v2out in the differential amplifier circuit. Equation for the voltage gain of the differential amplifier using one opamp can be derived as follows.
