***6.65 Consider the circuit shown in Fig. P6.65. It resembles that in Fig. 6.30 but includes other features. First, note diodes D 1 and D 2 are included to make design (and analysis) easier and to provide temperature compensation for the emitter–base voltages of Q 1 and Q 2 . Second, note resistor R, whose purpose is to provide negative feedback (more on this later in the book!). Using V BE and V D = 0.7 V independent of current, and β=∞, find the voltages V B1 , V E1 , V C1 , V B2 , V E2 , and V C2 , initially with R open-circuited and then with R connected. Repeat for β=100, with R open-circuited initially, then connected.

**6.63 It is required to design the circuit in Fig. P6.63 so that a current of 1 mA is established in the emitter and a voltage of −1 V appears at the collector. The transistor type used has a nominal β of 100. However, the β value can be as low as 50 and as high as 150. Your design should ensure that the specified emitter current is obtained when β=100 and that at the extreme values of β the emitter current does not change by more than 10% of its nominal value. Also, design for as large a value for R B as possible. Give the values of R B , R E , and R C to the nearest kilohm. What is the expected range of collector current and collector voltage corresponding to the full range of β values?