D 8.1 For V DD = 1.3 V and using IREF = 100 μA, it is required to design the circuit of Fig. 8.1 to obtain an output current whose nominal value is 100 μA. Find R if Q1 and Q2 are matched with channel lengths of 0.5 μm, channel widths of 5 μm, Vt = 0.4 V, and kn = 500 μA/V2. What is the lowest possible value of VO? Assuming that for this process technology the Early voltage VA = 5 V/μm, find the output resistance of the current source.Also,find the change in output current resulting from a +0.5-V change in VO.