As we know, one way of increasing the output resistance of MOS cascodes is via the telescopic technique. Telescoping, however, reduces the output voltage swing. A clever way to overcome this...

As we know, one way of increasing the output resistance of MOS cascodes is via the telescopic technique. Telescoping, however, reduces the output voltage swing. A clever way to overcome this limitation is to place the top FET inside a negativefeedback loop of the series-output type as depicted in Fig. P7.42. Assuming a CMOS op amp with av 5 103 V/V and FETs with gm 5 0.5 mA/V, ro 5 20 kV, and 5 0.1, fi nd Ro via Blackman’s impedance formula. What is the unloaded gain Aoc 5 voyvi ? Hint: select the dependent source modeling the op amp for your return-ratio calculations.