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How are you going to turn on or off the NPN transistor?
In short, a transistor conducts current across the collector-emitter path only when a voltage is applied to the base. When no base voltage is present, the switch is off. When base voltage is present, the switch is on.
When a transistor is on its collector voltage is?
Transistor datasheets will define this voltage as CE saturation voltage VCE(sat) — a voltage from collector to emitter required for saturation. This value is usually around 0.05-0.2V. This value means that VC must be slightly greater than VE (but both still less than VB) to get the transistor in saturation mode.
Why is the base voltage of an NPN transistor always positive?
The voltage between the Base and Emitter ( V BE ), is positive at the Base and negative at the Emitter because for an NPN transistor, the Base terminal is always positive with respect to the Emitter. Also the Collector supply voltage is positive with respect to the Emitter ( V CE ).
When does the voltage across the emitter-collector junction in NPN?
Otherwise, the emitter- collector junction can never be zero. It can be as low as the Vce (sat) (i.e., the saturation voltage when the transistor is in saturation), but that value will never be zero.
What happens if I bias the collector and emitter of an NPN?
(1). As the collector doping is less than the emitter doping, the hole current in the collector (now the emitter) increases, leading to lower beta. (2). The voltage withstand capability goes down, as now the BE junction is reverse biased, and the emitter is not constructed for high withstand voltage.
What is the voltage drop between collector and emitter?
The collector voltage, ( Vc ) must be greater and positive with respect to the emitter voltage, ( Ve ) to allow current to flow through the transistor between the collector-emitter junctions. Also, there is a voltage drop between the Base and the Emitter terminal of about 0.7V…