Assignment
The following assignment is for review of BJT & MOSFET based differential amplifiers (DAs). The assignment meets the ABET outcomes a, and e.
1. Design a bipolar DA that operates from ±2.5V power supplies and to provide a differential gain of -40V/V. The power dissipation in the quiescent state should not exceed 2 mW (ICQ X VCEQ). Show DC calculations, assuming β=100. (Problem D8.50 of 6th Edition of the Text).
2. A bipolar DA with RC=2 kΩ, REE=4.3kΩ, is operating from ±5 V. There's no biasing resistor in the base of the two BJTs. (Problem 8.62 of the 6th Edition of the Text).
a. Calculate the DC quiescent operating point.
b. Calculate the differential gain, common mode gain, and CMRR for the single ended DA.
3. An MOS DA that operates from a single 5V power supply (thus the common mode voltage cannot be zero). (Problem D 8.29 from the 6th Edition of the Text).
The dc bias current I is established to be 1 mA. The MOSFETs have the following parameters: kn=2.5 mA/V2, VTn=0.7V. The RSS=1 kΩ. Calculate the following:
a. Find the required DC voltage of VCM needed for the biasing of the transistor.
b. Find the value of RD that results in a differential gain of -8V/V.
c. Determine the DC voltage at the drains of the MOSFETs.
d. Determine the common mode gain of the DA.