I have been having some trouble designing a long-tailed pair transistor amplifier.
Vdd2 is 5V and the 6.8k ohm resistors were already given. I am trying to get a bias voltage of 0.8V at the transistor Q3, and the maximum voltage through the emitter of the transistor should be 1mA.
The first thing I did was to select values for Rb1 and Rb2, to set the base voltage for Q1 and Q2. The base voltage I am getting is around 1V. I am getting my calculated result from the LTspice simulation as well.
The emitter voltage of Q1 and Q2 must be 0.6V less than the base voltage. However I am getting 0.946V for the emitter voltage of Q1 and Q2, 0.09V at Vbias and 0v at the emitter of Q3.
How should I change my resistor values for Rc1, Rc2 and Re in order to get Vbias around 0.8V?