transistor 4

germanium transistor is about 10 microamperes. For a germanium transistor, the Icbo value doubles for every 12 ℃ increase in temperature, while for a silicon transistor, it doubles for every 8 ℃ increase in temperature. Although the Icbo value of a silicon transistor changes more dramatically with temperature, diode due to the fact that the Icbo value of a germanium transistor itself is larger than that of a silicon transistor, it is still heavily affected by temperature. In the amplification region, when the emitter junction of a transistor is in forward bias and the collector junction is in reverse bias operation, Ic approximately changes linearly with Ib, and the amplification region is the area where the transistor operates in the amplification state.diode

When both the emitter and collector junctions are in a positive bias state in the saturation region, Ic basically does not change with Ib and loses its amplification function.diode Based on the bias of the emitter and collector junctions of the transistor, its working state may be determined.diode

Figure 2: Input and output characteristics of a transistor

The cutoff region and saturation region are the areas where the transistor operates in a switching state. When the transistor is turned on, the operating point falls in the saturation region, and when the transistor is turned off, diode the operating point falls in the cutoff region.diode

3、 Main parameters of transistor

1. DC parameters

(1) The reverse saturation current Icbo between the collector and base, when the emitter is open (Ie=0) and a specified reverse voltage Vcb is applied between the base and collector, is only related to temperature and remains constant at a certain temperature. Therefore, it is called the reverse saturation current between the collector and base.diode  A good transistor has a very small Icbo. The Icbo of a low-power germanium transistor is about 1-10 microamperes, while the Icbo of a high-power germanium transistor can reach several milliamps. The Icbo of a silicon transistor is very small, at the nanoampere level.diode