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The circuit shown in Figure 1 is a modified Widlar current source. Given that the size ratios of M3:M4 = 1:1 and M5:M6 = 1:1. (a) Find the expression of IB in terms of circuit parameters: VTHN, μnCox, R1, (W/L)1 and (W/L)2. (3 marks) (b) Find the expression of the minimum VDD when only looking at current branch 1. ( 3 marks) (c) Find the expression of the minimum VDD when only looking at current branch 2. (3 marks) (d) Based on results in (b) and (c), find the minimum VDD. (1 mark) Figure 1

The circuit shown in Figure 1 is a modified Widlar current source. Given that the size ratios of M3:M4 = 1:1 and M5:M6 = 1:1. (a) Find the expression of IB in terms of circuit parameters: VTHN, μnCox, R1, (W/L)1 and (W/L)2. (3 marks) (b) Find the expression of the minimum VDD when only looking at current branch 1. ( 3 marks) (c) Find the expression of the minimum VDD when only looking at current branch 2. (3 marks) (d) Based on results in (b) and (c), find the minimum VDD. (1 mark) Figure 1

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The circuit shown in Figure 1 is a modified Widlar current source. Given that the size ratios of M3:M4 = 1 : 1 and M 5 : M 6 = 1 : 1 . (a) Find the expression of I B in terms of circuit parameters: V T H N , μ n C o x , R 1 , ( W / L ) 1 and ( W / L ) 2 . (3 marks) (b) Find the expression of the minimum V D D when only looking at current branch 1 . ( 3 marks) (c) Find the expression of the minimum V D D when only looking at current branch 2. (3 marks) (d) Based on results in (b) and (c), find the minimum V D D . (1 mark) Figure 1

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