Abstract of Design Differential Amplifier

For this project the differential amplifier is designed with the Single Ended input and the Single ended output by using the specific requirement like the gain of the non-inverting differential amplifier in this project is approximately 100-150 dB. The single ended input for the differential output circuit is converted into the single input for the differential input supply. By using the LTSpice design the differential amplifier is given below in the design section. By using BJT, analysis the non-inverting differential amplifier as shown in the DC, AC analysis

Introduction of Design Differential Amplifier

In this project report the topic is “Design of (DA) Differential Amplifier”. The DA “differential amplifier” is the kind of amplifier that is electronic give a difference among the two input voltages. Differential amplifier is the analog circuit of the two inputs that is    and  with a output where the output is directly proportional for a difference among a various voltages.

The A is a gain of an non-inverting differential amplifier; as know that about project the Gain (A) = 100->150

An OPA836 plus the OPA2836 is used for the non-inverting amplifiers by the single input for the non-inverting input,

Circuit give the signal gain; which is set by  ground as a reference for the output and input signals.  (Karki, 2011)

Production and the design for the high speed of differential amplifiers; then the silicon along with the germanium for the low voltage is used for the BiCMOS process. These process are very low voltage for the design of the amplifier that is incorporated for the output and inputs of the amplifier for regain the total maximum output swing of signal. The single ended application is also used the 3GHz bandwidth for the LRC 6406 for the I/O of the differential amplifier. (Brisebois, 2009)

The drawing of the amplifier circuits is simple, like the triangle shape, where the construction of the amplifier is irreverent, for the grater function of the circuits for the familiarizations. The non-inverting amplifier is presents in the Appendix 1;

Figure 1: Amplifiers Circuit Symbol

Background of Design Differential Amplifier

Operational Amplifier is on type of the Differential Amplifier; where the inputs and the outputs of the differential amplifier is include in the conventional Op-Amp. The gain of the non-inverting amplifier is around about 100-150 in this project report. (Brisebois, 2009)Many differential Amplifier is used to implement the basic two transistors for the circuits which is called the long-tailed pair for the differential amplifier. The main function of the differential amplifier has   inverting and the non-inverting terminals, that these terminals are used for the input which is opposed of the being input connected to the ground. The significant function of the Differential amplifier is that, it amplifies a variations among the two input voltages. In the most application of the Differential Amplifier the transfer function is most important in the analog computers. At the input terminal have the high input in the output terminal contains the high output which is used in particular significant feature of the amplifier.    

There are four configuration where differential amplifier is operated;

Output of Differential Amplifier is balanced with Dual Input    

Output of Differential Amplifier is unbalanced with Dual Input   

Output of Differential Amplifier is balanced with Single Input

Output of Differential Amplifier is Unbalanced with Single Input   

Figure 2: Configuration of Differential amplifier

The configuration of the DA is shown in the above figure, where the number of the input signals is utilized for the way of the output voltage is calculated, configuration is the dual input are used the two input signals, otherwise a configuration is single input. (Nptel.Ac.In/Courses, n.d.)

Signal of a Common mode which are drives from an inputs of the amplifier; this signal is interference, statics by the various kinds of the pickups, where the connecting wires for the input bases the liked the small antennas. Operating environment of the differential amplifier by the interference of the electromagnetic with the voltage that is unwanted interference for a transistors to coordinate in the every respects by an output which is balanced. This the significant characteristics of differential amplifier, against the common mode signal, it discriminates for the input signals, and otherwise it refuses the common mode signal to amplify. (Nptel.Ac.in/Courses, n.d.)

Methodology of Design Differential Amplifier

Circuit of the Differential Amplifier

Figure 3: Differential amplifier Circuits

DC Analysis of Design Differential Amplifier

For the I_CC as well as V_CEQ  on the behalf of  the amplifier  of the DC circuits which is shown by the reduction of  an inputs voltages V₁ as well as  V₂ as presents in the below schematics ; (Nptel. Aac.in/courses, n.d.)

Figure 4: DC Analysis of Differential Amplifier

Applying the KVL for the base emitter loop of Q1

AC Analysis of Design Differential Amplifier

Figure 5: AC Analysis of Differential Amplifier

Output voltages of the gain is given by

The non- inverting different amplifier is shown in the appendix 3 with the specific calculations

Calculation of CMMR of Design Differential Amplifier

Now 1^st of develop the SPICE model for the CMR to understand the op-amp CMRR. CMRR is the measures, in what the devise is rejects for the CM signal

Figure 6: CMR model

Bandwidth of Design Differential Amplifier

When design the non-inverting differential amplifier, then the bandwidth is significant;

Gain bandwidth product = Av * f

Where the frequency response in this model include the zero approximations for the CMRR behaviour of the frequency. LCM of inductor is together by RCM to create the zero at

=

LT Spice of Design Differential Amplifier

For the electronic circuit implement the SPICE simulators, LTSpice is the freeware computer software, which is produced the manufacturing of the technology which is linear for the part of analog devise. Waveform viewer and the schematic capture is obtained from the LTSpice by the improvements of the speed models for the simulations of the regulators as well as Switching. By the LTspice mostly model are 80 % of the liner technology for the regulators and switching as well as differential Amplifier, MOSFET plus the passive components. The schematic of LTspice is stored in the ASCII text as the extension “asc” which is consist for the netlist on the SPICE of commands.  

Circuit Construction of Design Differential Amplifier

Figure 7: Circuit Construction

Design of Circuit of Design Differential Amplifier

Figure 8: Design Circuit of Non-inverting Amplifier

Above circuit is the non-inverting differential amplifier; that is implemented on the SPICE, the results of this circuits give the AC waveform which is our desired results. As you can check the below simulations result.

Simulation Results of Design Differential Amplifier