Instruction: Use any circuit simulation tool to answer the problems below.

1. A BJT differential amplifier is biased from a 2-mA constant-current source and includes a 100-2 resistor in each emitter. The collectors are connected to +10 V via 5 k

resistors. A differential input signal of 0.1 V is applied between the two bases. Assume that the transistors are matched and have ß-100 and Is=14 fA.

(a) With the aid of LTSpice (or any other circuit simulation tool), determine the signal current in the emitters i, and the base-emitter voltage vibe for each BJT.

(b) What is the total emitter current in each BJT?

(c) What is the signal voltage at each collector?

(d) What is the voltage gain realized when the output is taken between the two collectors?

R₁ =

5 ΚΩ

Q₁

+5 V

-5 V

2 mA

Q2

02

R₂ =

5 ΚΩ

Vi

Ri

Vcc = +10 V

150

150 Ω

0.5 mA

20 ΚΩ