Single Input Unbalanced Output Differential Amplifier: Single input unbalanced output differential amplifier configurations are rarely used. The reasons for this are as follows: This configuration is identical to the CE amplifier but it needs comparatively more components and yields less voltage gain than that of CE amplifier. A dc output voltage exists even in absence […]
Single Input Unbalanced Output Differential Amplifier Read More »
Single Input Balanced Output Differential Amplifier: In a single input balanced output differential amplifier an input signal is applied to either input, with the other input connected to ground. However, due to the common-emitter connection the input signal operates both transistors, resulting in output from both collectors. Single input balanced output differential amplifier is depicted
Single Input Balanced Output Differential Amplifier Read More »
Dual Input Unbalanced Output Differential Amplifier: It is an important configuration and converts dual inputs into a single ended output. In this configuration, two input signals are applied and the output is measured at only one of the two collectors (either at C1 or at C2) with respect to ground. The output is called the
Dual Input Unbalanced Output Differential Amplifier Read More »
Dual Input Balanced Output Differential Amplifier: The dual input balanced output differential amplifier configuration is shown in Fig. 20.2. In the given circuit two input signals vin1 and vin2 are applied to the bases B1 and B2 of transistors Q1 and Q2. The differential input under amplification is the difference of the two input signals vin1
Dual Input Balanced Output Differential Amplifier Read More »
Feedback Pair Connection – Operation and its Equivalent Circuit: The feedback pair connection (Fig. 19.58) is a two-transistor circuit that operates like the Darlington amplifier. It makes use of a PNP transistor driving an NPN transistor, the two devices acting much like one PNP transistor. Like Darlington amplifier the feedback pair connection also provides a
Feedback Pair Connection – Operation and its Equivalent Circuit Read More »
Bootstrapped Darlington Circuit Operation and its Equivalent Circuit: The maximum input resistance of a Darlington circuit is limited to 1/hob ≡ 2 MΩ, as 1/hob is the resistance between base and collector. However, the input resistance can be largely increased by bootstrapped darlington circuit through the addition of capacitor C’ between the first collector terminal
Bootstrapped Darlington Circuit Operation and its Equivalent Circuit Read More »
Darlington Pair Transistor – Circuit Diagram and its Workings: A very popular connection of two BJTs for operation as one “superbeta” transistor is the Darlington connection. In practice, the two transistors are put inside a single package and three terminals E, B and C are brought out, as depicted in Fig. 19.52. The main feature
Darlington Pair Transistor – Circuit Diagram and its Workings Read More »
Darlington Amplifier – Circuit Diagram, Characteristics, Merits and Applications: Darlington amplifier with voltage divider bias is shown in Fig. 19.50. In this circuit the output of one amplifier is coupled into the input of the next one by directly joining emitter of one transistor to the base of the other one, as shown in the
Darlington Amplifier – Circuit Diagram, Characteristics, Merits and Applications Read More »
Emitter Follower at High Frequencies: Emitter Follower at High Frequencies circuit is given in Fig. 19.48(a). A capacitance CL is included across the load because the emitter follower is often used to drive capacitive loads. This is because of its small output impedance. Applying Kirchhoff’s current law to nodes B′ and E respectively [Fig. 19.48(b)],
Emitter Follower at High Frequencies Read More »
Emitter Follower Circuit – Operation, Advantages and Applications: Emitter Follower Circuit is also a negative current feedback circuit. This circuits exhibits a large input impedance, a small output impedance, and a voltage gain of approximately unity. Further the output voltage tends to be in phase with the input voltage—hence the term “follower”. At first glance,
Emitter Follower Circuit – Operation, Advantages and Applications Read More »
