D 8.67 Design the CMOS cascode amplifier in Fig. 8.33 for the following specifications: gm1 = 1 mA/V and Av = -280 V/V. Assume that for the available fabrication process, /V1A / = 5 V/μm for both NMOS and PMOS devices and that μnCox =4 μpCox =400 μA/V2. Use the same channel length L for all devices and operate all four devices at /VOV / =0.25 V. Determine the required channel length L, the bias current I, and the W/L ratio for each of four transistors. Assume that suitable bias voltages have been chosen, and neglect the Early effect in determining the W/L ratios.