D *8.64 For a cascode current source, such as that in Fig. 8.32, show that if the two transistors are identical, the current I supplied by the current source and the output resistance R o are related by Now consider the case of a 0.18-μm technology for which  V A  = 5 V/μm and let the transistors be operated at  V OV  = 0.2 V. Find the figure-of-merit IRo for the three cases of L equal to the minimum channel length, twice the minimum, and three times the minimum. Complete the entries of the table at the bottom of the page. Give W/L and the area 2WL in terms of n, where n is the value of W/L for the case I = 0.01 mA. In the table, Av denotes the gain obtained in a cascode amplifier such as that in Fig. 8.33 that utilizes our current source as load and which has the same values of gm and R o as the current-source transistors. (a) For each current value, what is price paid for the increase in R o and Av obtained as L is increased? (b) For each value of L, what advantage is obtained as I is increased, and what is the price paid? (Hint: We will see in Chapter 10 that the amplifier bandwidth increases with gm.) (c) Contrast the performance obtained from the circuit with the largest area with that obtained from the circuit with the smallest area

8.64 - D *8.64 For a cascode current source, such as that in Fig. 8.32, show that if the two transistors are identical, the current I supplied by the current source and the output resistance R o are related by Now consider the case of a 0.18-μm technology for which  V  A  = 5 V/μm and let the transistors be operated at  V OV  = 0.2 V. Find the figure-of-merit IRo for the three cases of L equal to the minimum channel length, twice the minimum, and three times the minimum. Complete the entries of the table at the bottom of the page. Give W/L and the area 2WL in terms of n, where n is the value of W/L for the case I = 0.01 mA. In the table, Av denotes the gain obtained in a cascode amplifier such as that in Fig. 8.33 that utilizes our current source as load and which has the same values of gm and R o as the current-source transistors. (a) For each current value, what is price paid for the increase in R o and Av obtained as L is increased? (b) For each value of L, what advantage is obtained as I is increased, and what is the price paid? (Hint: We will see in Chapter 10 that the amplifier bandwidth increases with gm.) (c) Contrast the performance obtained from the circuit with the largest area with that obtained from the circuit with the smallest area

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images - D *8.64 For a cascode current source, such as that in Fig. 8.32, show that if the two transistors are identical, the current I supplied by the current source and the output resistance R o are related by Now consider the case of a 0.18-μm technology for which  V  A  = 5 V/μm and let the transistors be operated at  V OV  = 0.2 V. Find the figure-of-merit IRo for the three cases of L equal to the minimum channel length, twice the minimum, and three times the minimum. Complete the entries of the table at the bottom of the page. Give W/L and the area 2WL in terms of n, where n is the value of W/L for the case I = 0.01 mA. In the table, Av denotes the gain obtained in a cascode amplifier such as that in Fig. 8.33 that utilizes our current source as load and which has the same values of gm and R o as the current-source transistors. (a) For each current value, what is price paid for the increase in R o and Av obtained as L is increased? (b) For each value of L, what advantage is obtained as I is increased, and what is the price paid? (Hint: We will see in Chapter 10 that the amplifier bandwidth increases with gm.) (c) Contrast the performance obtained from the circuit with the largest area with that obtained from the circuit with the smallest area

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