PHYS345 Electricity and Electronics

Answer for P14.2

Availability of a -5 V supply makes is easy: Use Rf = Ri and tie v2 at -5 V.

To use a different voltage requires a voltage divider. Then we seek a voltage divider of -15 V to ground via R4 and R3 in series such that its Thevenin equivalent is the same as -5 V and Rf above.

If Rf = 10k above, then R4 = 30k and R3 = 15k works.

Differential amplifier with voltage divider

Last updated Dec. 4, 1998.
Copyright George Watson, Univ. of Delaware, 1998.