Why input resistance of a transistor is low?
While using a transistor, the emitter-base junction is always forward biased and the collector-base junction is always reverse-biased. Due to it, a small change in emitter current. This means that a small signal voltage variation at the input of the transistor produces a large emitter current variation. This showed that the input resistance of a transistor is low. Since the collector is reverse-biased, it collects all the charge carriers which diffuse into it, through the base. Due to it, a very large change in collector voltage shows only a small change in the collector current. This shows that the output resistance of the transistor is high.
How to Calculate Emitter Resistance given Threshold Voltage?
Emitter Resistance given Threshold Voltage calculator uses Emitter Resistance = Threshold Voltage/Emitter Current to calculate the Emitter Resistance, The Emitter Resistance given threshold voltage suggests that for a small signal, the transistor behaves as a voltage-controlled current source. The input port of the controlled current source is between base and emitter and the output port is in between collector and emitter. Emitter Resistance is denoted by Re symbol.
How to calculate Emitter Resistance given Threshold Voltage using this online calculator? To use this online calculator for Emitter Resistance given Threshold Voltage, enter Threshold Voltage (Vth) & Emitter Current (Ie) and hit the calculate button. Here is how the Emitter Resistance given Threshold Voltage calculation can be explained with given input values -> 0.001083 = 5.5/0.005077.