If the pnp transistor is characterized by its exponential relationship with a scale current IS , show
that the dc current I is determined by IR = VT ln(I/IS ). Assume Q1 and Q2 to be matched, and
Q3, Q4, and Q5 to be matched. Find the value of R that yields a current I = 200\mu A. For the BJT,
VEB = 0.7V at IE = 1mA.