Microelectronic Circuit Design

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CHAPTER 15 15.1 a ( ) I C = α F I E = 1 2 β F β F + 1 12 V BE R EE = 1 2 100 101 12 0.7 2.7 x 10 5 = 20.7 µ A | V C = 12 3.3 x 10 5 I C = 5.17 V V CE = V C − − 0.7 V ( ) = 5.87 V | Q Point = 20.7 µ A , 5.87 V ( ) b ( ) A dd = − g m R C = − 40 20.7 µ A ( ) 330 k ( ) = − 273 R id = 2 r π = 2 β o V T I C = 2 100 0.025 V ( ) 20.7 µ A = 243 k | R od = 2 R C = 660 k c ( ) A cc = − β o R C r π + β o + 1 ( ) 2 R EE = − 100 330 k ( ) 122 k Ω + 2 101 ( ) 270 k = − 0.604 A dd = − g m R C 2 = − 137 | A cd = A cc | CMRR = 137 0.604 = 227 or 47.1 dB (very low) R ic = r π + β o + 1 ( ) 2 R EE 2 = 122 k Ω + 2 101 ( ) 270 k 2 = 27.3 M 15.2 a ( ) I E = 1 2 1.5 0.7 75 x 10 3 V = 5.33 µ A | I C = α F I E = 60 61 I E = 5.25 µ A V CE = 1.5 10 5 I C − − 0.7 ( ) = 1.68 V | Q - Pt : 5.25 µ A , 1.68 V ( ) b ( ) g m = 40 I C = 0.210 mS | r π = 60 g m = 286 k | A dd = − g m R C = − 0.210 mS 100 k ( ) = − 21.0 A cc = − β o R C r π + β o + 1 ( ) 2 R EE = − 60 100 k ( ) 286 k Ω+ 61 150 k ( ) = − 0.636 For differential output : CMRR = 21.0 0 = ∞ For single - ended output : CMRR = 21.0 2 0.636 = 16.5, a paltry 24.4 dB! R id = 2 r π = 572 k | R ic = r π + β o + 1 ( ) 2 R EE 2 = 286 + 61 150 ( ) 2 k Ω = 4.72 M R od = 2 R C = 200 k | R oc = R C 2 = 50 k 15.3 ©Richard C. Jaeger and Travis N. Blalock - 3/10/07 15-1
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