Bipolar Junction Transistor Configuration Voltage and current gain are both present in this 1 Common Emitter Configuration. 2: The Common Collector Configuration has a current gain but no voltage gain. 3: The typical base design offers a voltage gain but no current gain. 4: The BiFET (bio-electronic transistor) has neither current nor voltage gain.
5: The HBT (heterojunction bipolar transistor) has a voltage gain but no current gain.
The BVT (buried vertical transistor) has no current or voltage gain.
The MCT (merged collector transistor) has no current gain but does have voltage gain.
The HEMT (hybrid electron motor transistor) has voltage and current gain.
The HBT/PHEJ (high performance heterojunction bipolar transistor/premium hybrid electron jet) has both voltage and current gain.
The LEPHT (lateral emitter-passivated hot-carrier transistor) has current gain but no voltage gain.
The MESFET (metal semiconductor field effect transistor) has no current gain but does have voltage gain.
The MJDST (molecular junctions diode switch) has no current or voltage gain.
Introduction There is one base in common (CB) Configuration: there is no current gain, but there is voltage gain. CC 2: (Common Collector) Current gain but no voltage gain is the configuration. 3 ECT (Common Emitter) Voltage gain and current gain are configured. 4 PNP (Power Negative Power) The NPN transistor has its collector connected to its emitter, while in the PNP transistor these connections are reversed.
When the base-to-collector voltage is constant, the current gain for the common-base arrangement is defined as the change in collector current divided by the change in emitter current. In a well-designed bipolar transistor, the usual common-base current gain is extremely near to unity. He has the most helpful amplifier he has.
The current gain of a bipolar transistor depends on two factors: first, the bias conditions applied to the base-emitter junction; second, the structure of the device itself. Under balanced conditions (equal currents flowing into and out of the base), the current gain is equal to the ratio of the emitter areas for the two branches of the circuit. For example, if one branch has an area of 1 mm2 while the other has an area of 0.5 mm2, the current gain is 2. Because current gains greater than 1 are more commonly found in practical devices, this type of arrangement would be expected to produce unstable behavior in which the output signal would grow without limit until something shuts off the input signal.
Current gain can also be defined as the ratio of the transistors' emitter resistances under equal current flows into and from the base. The current gain is therefore the same for both branches of the common-base amplifier. It does not depend on the size of these currents or their relative magnitudes. If one branch of the amplifier is driven by a current source then the other branch will have the same current regardless of its actual value.
Common emitter transistor arrangement Both current and voltage gain may be defined as medium, however the output is the inverse of the input, resulting in a 180 degree phase shift. As a result of its high overall performance, this is frequently the most popular configuration. The common collector configuration Current gain only; no voltage gain Vce (emitter bias) must be low enough to allow linear operation in the active region Of secondary importance compared to the common emitter case because it is the inverse of that configuration. The common base configuration Voltage gain only; no current gain Vbe (base-emitter bias) must be low enough to allow linear operation in the active region Again, because it is the inverse of the common emitter configuration, these devices usually have very similar performance characteristics.
The fundamental architecture of a bipolar transistor consists of two PN-junctions that produce three connecting terminals, each of which is given a name to distinguish it from the other two. These three terminals are designated as the emitter (E), base (B), and collector (C), in that order. The base terminal connects directly to the positive pole of the power supply voltage, while the collector terminal connects directly to the negative pole of the power supply voltage.
These three connections represent all the pathways through which current can flow between the positive and negative poles of the power supply. A schematic diagram describing the function of a bipolar transistor is shown below. E indicates the emitter terminal, B indicates the base terminal, and C indicates the collector terminal.
In general, electric current flows from the collector to the emitter in a bipolar transistor. But, since we want our transistors to operate like diodes, we need a way to reverse the direction of this current flow. This is where the base region comes into play. If we connect the base terminal to the negative power supply pole then when you apply a positive voltage to the emitter terminal current will flow from the emitter to the base, turning on the transistor. But if we now connect the base terminal to the positive power supply pole then no current will flow to the emitter because there is no path from the positive pole to the negative pole through your transistor.
This article describes how to properly bias bipolar transistors. As an example, consider the Common Emitter Amplifier (CEA) arrangement to be explored. The CEA is one of three basic bipolar transistor designs used to create a signal amplifier. The other two are the Transistor-Transistor Logic (TTL) and Metal-Oxide-Semiconductor (MOS) circuits. A CEA has two bases connected together and to the emitter of the input transistor. The third base is connected directly to the emitter of the output transistor. When you apply a voltage to the base leading the current path that includes the emitter of the input transistor, this turns on both of them. Then when you connect the collector of the input transistor to its base, it will drive the collector into saturation. This closes the loop so that current will flow from the collector of the input transistor to the emitter of the output transistor until they both turn off.
Bipolar transistors need to be biased for two main purposes: first, to avoid unnecessary power consumption; second, to get the best performance from the device. There are two ways to bias a bipolar transistor: directly or indirectly. In direct biasing, the collector current of the transistor is controlled by applying voltages to its base and emitter. Indirect biasing does not depend on controlling the collector current but instead uses another part of the circuit to control it.