Homework $12$

Problem $1(3+4$ pt$)$

For the adjacent circuit, the op$-$amp is ideal. The diode can be modeled with a constant voltage drop model having a $0\mathrm{.}7$ volt drop when it is on$.$

a$)$ Find the value of Vs that puts the diode at the boundary between on and off $($meaning that the diode is ON$,$ but current is approaching zero$).$

b$)$ Make a plot of Vo versus Vs$.$

Note: Justify all assumptions briefly but clearly.