BC490G

The BC490G is a single, bipolar junction transistor (BJT) utilized in various electrical applications. Having a PNP structure, the device offers low reverse saturation voltage, hFE of 50-200, max collector current IC of 600mA, and collector-emitter voltage VCEO of 40V. Its varicap properties also make it applicable in oscillator circuits. Bipolar junction transistors (BJTs) represent basic electronic components that allow current flow in either direction between the two terminals, commonly known as the collector and the emitter electrodes. The third terminal is the base, used to control current flowing between the two others by means of a biased potential.In a NPN-type BJT, the control of current is achieved by the flow of electrons injected from the base into the emitter. By applying a voltage, of opposite polarity to that of the base-emitter junction, the electrons cross the junction, eliminating minority carriers, collecting in the collector region and, therefore, increasing the current from the collector to the emitter. This process is known as “Forward-Bias” and the collector current is near to its maximum value (Ic).In contrast, when the voltage of the base-emitter junction is of the same polarity, the electrons reach the emitter terminal and the majority carriers become minority in the emitter region. The collector current is near to its minimum value (Ie). This phenomenon is defined as “Reverse-Bias”.The BC490G can demonstrate both “forward bias” and “reverse bias” on its junctions, depending on the type of charge applied. Due to its maximum current Ic of 600mA, and a negative collector-emitter saturation voltage of -0.1V at 500μA, the active BC490G has the capacity of becoming a suitable compact switch to control large amounts of current in a short period of time; the voltage drop can be higher for the same base current. Moreover, due to its low reverse saturation voltage, the device will require a small base current to reach the maximum operating value, making it suitable for low power circuits. In addition to its applications as a switch, Another interesting function of the BC490G is as a variable capacitor. This use is related to the property of this device of having a very low reverse saturation voltage, ranging from -0.5V to -1.5V (depending on the DC base current). By applying a voltage at the control gate of the device, its transistor properties vary, resulting in different capacitance values at the base-collector and base-emitter junctions.This phenomena, called capacitance modulation, can be useful as a frequency tuner in elementary oscillators, as it will provide small, predictable shifts of the operating frequency. In this regard, the emitter-collector time constant τ can also be modified using the base-emitter junction as a capacitor, thanks to the low reverse saturation voltage and the rapid switching times of the device.In conclusion, the BC490G transistor is a single, universal bipolar junction transistor (BJT) commonly utilized in numerous electrical applications. It can be used to control large currents and as a varicap diode due to its low reverse saturation voltage and carrier modulation properties. Additionally, it offers a max collector current Ic of 600mA and collector-emitter voltage VCEO of 40V, making it a strong and reliable device for both analog and digital tasks.

BC490	ON Semicondu...	0.0 $	1000	TRANS PNP 80V 1A TO-92Bip...
BC490A	ON Semicondu...	0.0 $	1000	TRANS PNP 80V 1A TO-92Bip...
BC490AG	ON Semicondu...	0.0 $	1000	TRANS PNP 80V 1A TO-92Bip...
BC490AZL1	ON Semicondu...	0.0 $	1000	TRANS PNP 80V 1A TO-92Bip...
BC490AZL1G	ON Semicondu...	0.0 $	1000	TRANS PNP 80V 1A TO-92Bip...
BC490G	ON Semicondu...	0.0 $	1000	TRANS PNP 80V 1A TO-92Bip...