$190$

The Operational Amplifier

ASSESSMENT PROBLEM

Objective $2-$Be able to analyze simple circuits containing ideal op amps

$5\mathrm{.}4$ Assume that the op amp in the circuit shown is ideal.

a$)$ Find the output voltage when the variable resistor is set to $60k.$

b$)$ How large can $R_x$ be before the amplifier saturates?

Answer: $($a$)4\mathrm{.}8$ V ;

$($b$)75k.$

SELF$-$CHECK: Also try Chapter Problems $5\mathrm{.}18$ and $5\mathrm{.}20.$

$5\mathrm{.}6$ The Difference$-$Amplifier Circuit

The output voltage of a difference amplifier is proportional to the ference between the two input voltages. To demonstrate, we analyz it difference$-$amolifier circuit shown in Fio $515$ minn $$ nalvsis Methody