Response to the following problem:
Design a BJT differential amplifier that provides two single-ended outputs (at the collectors). The amplifier is to have a differential gain (to each of the two outputs) of at least 100 V/V, a differential input resistance ≥ 10 kΩ, and a common-mode gain (to each of the two outputs) no greater than 0.1 V/V. Use a 2-mA current source for biasing.
Give the complete circuit with component values and suitable power supplies that allow for ± 2 V swing at each collector. Specify the minimum value that the output resistance of the bias current source must have. If the current source is realized by a simple mirror, what must the minimum value of VA be? The BJTs available have β ≥ 100. What is the value of the input common-mode resistance when the bias source has the lowest acceptable output resistance?