Contents
When does the collector current increase in a BJT?
The collector current is extremely small until V IN reaches approximately 0.6 V. After that, the transistor is in forward active mode, and collector current increases rapidly. Then, at V IN ≈ 1.05 V, the collector current reaches the point at which the voltage dropped across R C is large enough to move the BC junction into the forward-bias region.
What are the maximum junction voltages for a BJT?
On the datasheet for a BJT, there are normally 3 maximum junction voltages specifications that are given: VCEO, VCBO, and VEBO. In this article, we will explain what the these ratings for VCEO, VCBO, and VEBO are and why they have value for circuit designers using these transistors.
How is the collector – emitter current related to the current of the collector?
The collector–emitter current can be viewed as being controlled by the base–emitter current (current control), or by the base–emitter voltage (voltage control). These views are related by the current–voltage relation of the base–emitter junction, which is the usual exponential current–voltage curve of a p–n junction (diode).
When does the BJT enter forward active mode?
V OUT, which is the same as the collector voltage, begins at 5 V and decreases as increasing collector current causes a progressively larger voltage drop across R C. As explained above, the BJT exits forward active mode when the base-to-collector voltage is 0.5 V, which corresponds to a collector voltage of 0.2 V.
How to analyze BJT circuit with d.c.sources?
To analyze BJT circuit with D.C. sources, we mustfollow these five steps: 1. ASSUME an operating mode 2. ENFORCE the equality conditions of that mode. 3. ANALYZE the circuit with the enforced conditions. 4. CHECK the inequality conditions of the mode for consistency with original assumption.
Which is the most important characteristic of a BJT?
In order to distinguish these regimes we have to look at the i-v characteristics of the device. The most important characteristic of the BJT is the plot of the collector current, IC, versus the collector-emitter voltage, VCE, for various values of the base current, IBas shown on the circuit of Figure 6.