Search results
Results From The WOW.Com Content Network
A load line diagram, illustrating an operating point in the transistor's active region.. Biasing is the setting of the DC operating point of an electronic component. For bipolar junction transistors (BJTs), the operating point is defined as the steady-state DC collector-emitter voltage and the collector current with no input signal applied.
In electronics, leakage is the gradual transfer of electrical energy across a boundary normally viewed as insulating, such as the spontaneous discharge of a charged capacitor, magnetic coupling of a transformer with other components, or flow of current across a transistor in the "off" state or a reverse-polarized diode.
The Gummel–Poon model and modern variants of it are widely used in popular circuit simulators such as SPICE. A significant effect that the Gummel–Poon model accounts for is the variation of the transistor β F {\displaystyle \beta _{\text{F}}} and β R {\displaystyle \beta _{\text{R}}} values with the direct current level.
3D model of a TO-92 package, commonly used for small bipolar transistors. A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor (FET), uses only one kind of charge carrier.
The transistor is said to be cut off, passing only a very small leakage current, and so very nearly the entire supply voltage appears as V CE. The operating point of the circuit in this configuration (labelled Q) is generally designed to be in the active region , approximately in the middle of the load line's active region for amplifier ...
In fact, there is a current even for gate biases below the threshold (subthreshold leakage) current, although it is small and varies exponentially with gate bias. Therefore, datasheets will specify threshold voltage according to a specified measurable amount of current (commonly 250 μA or 1 mA).
Figure 1: Basic NPN common collector circuit (neglecting biasing details).. In electronics, a common collector amplifier (also known as an emitter follower) is one of three basic single-stage bipolar junction transistor (BJT) amplifier topologies, typically used as a voltage buffer.
The current gain is very nearly unity as long as R S ≫ r E. An alternative analysis technique is based upon two-port networks. For example, in an application like this one where current is the output, an h-equivalent two-port is selected because it uses a current amplifier in the output port.