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In this article we will discuss regarding beta (β) and what is hFE in BJT configurations. We will find the similarity between ac and dc betas, and also prove through formulas why the factor beta is so important in BJT circuits. A BJT circuit in the dc bias mode forms a relationship across its collector and … Read moreWhat is beta (β) in BJTs
By far the most commonly used transistor configuration can be seen in Fig. 3.13 below for both pnp and npn transistors. This configuration is known as common-emitter configuration because the emitter is common, or becomes the reference terminal to both the input and output stages (meaning common to both the base and collector terminals). Just … Read moreUnderstanding Common Emitter Configuration in BJTs
In this section we are going to analyze BJT common-base configuration, and learn regarding its driving point characteristics, reverse saturation current, base to emitter voltage and evaluate the parameters through a practical solved example. In the later parts we will also analyze how to configure a common-base amplifier circuit Introduction The symbols and annotations utilized … Read moreUnderstanding Common Base Configuration in BJTs
How Bipolar Junction Transistor BJTs Evolved During 1904–1947, the vacuum tube was unquestionably the electronic device of great curiosity and growth. In 1904, the vacuum-tube diode was launched by J. A. Fleming. Soon afterwards, in 1906, Lee De Forest enhanced the device with a third feature, known as the control grid, producing the first amplifier, and … Read moreBipolar Junction Transistor (BJT) – Construction, and Operational Details
In the previous bias designs that we learned the bias current ICQ and voltage VCEQ were a function of the current gain (β) of the BJT. But, as we know that β can be vulnerable to temperature changes, particularly for silicon transistors, and also the true value of beta is often not properly identified, it could … Read moreVoltage-Divider Bias in BJT Circuits – More Stability without beta Factor
We have already studied what is DC biasing in transistors, now let’s move ahead and learn how an emitter resistor can be used for improving the stability of a BJT DC bias network. Applying Emitter Stabilized Bias Circuit The inclusion of the emitter resistor to the dc bias of the BJT delivers superior stability, meaning, … Read moreEmitter-Stabilized BJT Bias Circuit