Emitter biasing , as shown in Figure 15-1, requires two separate dc voltage sources, one
Positive and one negative. Voltage source Vcc is the positive dc source and Voltage source Vee is the negative dc source. Kirchoff’s voltage law applied to the base-emitter
Circuit gives the equation
VEE = IBRB+VBE+IERE
The base voltage (VB) for the emitter-biased transistor circuit is negative and is equal to the
Voltage across the base resistor (RB) due to the base currunt (IB). Therefore,
VB = -IBRB
And
VEE = -VB + VBE+ IERE
Solving for the emitter the emitter current gives the equation
IE = (V_(EE+) V_B-V_BE)/R_E