org Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ Chapter 1 1.1 − Eg / 2 kT ni = BT 3 / 2 e (a) Silicon ⎡ −1. ni = BT 3 / 2 exp ⎜ ⎟ ⎝ 2kT ⎠ ⎛ −1.91× 10−4 = T 3 / 2 exp ⎜ − ⎟ ⎝ T ⎠ By trial and error, T ≈ 368 K b.91× 10−7 = T 3 / 2 exp ⎜ − ⎟ ⎝ T ⎠ By trial and error, T ≈ 268° K ______________________________________________________________________________________ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1.4 (a) n-type; no = 10 15 −3 n2 cm ; po = i = 2.76 × 10 cm 2 11 −3 no 1015 ni2 (b) n-type; no = 1015 cm −3 ; po = = 1.25 × 10 5 cm −3 )2 no 1015 ______________________________________________________________________________________ www.org Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1.5 (a) p-type; p o = 1016 cm −3 ; no = ni2 = ( 1.24 × 10 2 −4 cm −3 po 1016 ni2 (b) p-type; p o = 1016 cm −3 ; no = = 2.5 × 103 cm −3 no 5 × 1016 (c) no = N d = 5 × 1016 cm −3 From Problem 1.7 (a) p-type; p o = 5 × 1016 cm −3 ; no = ni2 = ( 1.5 × 10 cm 2 3 −3 po 5 × 1016 ni2 = 1.8 × 10 6 (b) p-type; p o = 5 × 1016 cm −3 ; no = ( = 6.5 × 104 cm −3 no 5 × 1015 (b) n o > p o ⇒ n-type (c) no ≅ N d = 5 × 1015 cm −3 ______________________________________________________________________________________ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1. Add Donors N d = 7 × 1015 cm −3 b. Want po = 106 cm −3 = ni2 / N d So ni2 = (106 )( 7 × 1015 ) = 7 × 10 21 ⎛ − Eg ⎞ = B 2T 3 exp ⎜ ⎟ ⎝ kT ⎠ ⎛ −1.23 × 1015 ) T 3 exp ⎜ 2 ⎟ ⎜ ( 86 × 10 ) (T ) ⎟ −6 ⎝ ⎠ By trial and error, T ≈ 324° K ______________________________________________________________________________________ 1.36 ×103 A / cm2 ______________________________________________________________________________________ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1.7 cm 2 /s ⎛ 1016 − 1012 ⎞ J n = eDn dn ( ) = 1.001 ⎠ Total diffusion current density J = −52 − 18.17 dp J p = −eD p dx ⎛ −1 ⎞ ⎛ −x ⎞ = −eD p (10 15 ) ⎜ ⎟ exp ⎜ ⎟ ⎜ Lp ⎟ ⎜ Lp ⎟ ⎝ ⎠ ⎝ ⎠ Jp = (1.6 ×10 ) (15) (10 ) exp ⎛ − x ⎞ −19 15 ⎜⎜ ⎟⎟ 10 × 10 −4 ⎝ Lp ⎠ − x / Lp J p = 2. N a = 1017 cm −3 ⇒ po = 1017 cm −3 n 2 (1.19 Vbi = VT ln⎜⎜ a 2 d ⎟⎟ ⎝ ni ⎠ (a) (i) ( ⎡ 5 × 1015 5 × 1015 ⎤ Vbi = (0.org Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ (b) (i) ( )( ⎡ 5 × 1015 5 × 1015 ⎤ Vbi = (0.20 ⎛N N ⎞ Vbi = VT ln⎜⎜ a 2 d ⎟⎟ ⎝ ni ⎠ or Na = (n ) exp⎛⎜ V ⎞⎟ = (1.76 × 10 2 i bi 2 cm 16 −3 ⎜V ⎟ 1016 Nd ⎝ T ⎠ ⎝ 0.21 ⎛N N ⎞ ⎡ N a (1016 ) ⎤ Vbi = VT ln ⎜ a 2 d ⎟ = ( 0.5 × 10 ) ⎥⎦ 10 2 ⎝ ni ⎠ For N a = 1015 cm −3 , Vbi = 0.637 V For N a = 1018 cm −3 , Vbi = 0.3 Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ ⎛ −1.1× 1014 )(T 3 / 2 ) exp ⎜ ⎟ ⎜ 2 ( 86 × 10−6 ) (T ) ⎟ ⎝ ⎠ ⎛N N ⎞ Vbi = VT ln ⎜ a 2 d ⎟ ⎝ ni ⎠ T ni Vbi 200 1.24 −1 / 2 ⎛ V ⎞ (a) C j = C jo ⎜1 + R ⎟ ⎝ Vbi ⎠ −1 / 2 ⎛ 5 ⎞ For VR = 5 V, C j = (0. 8 ⎠ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 0.44 × 10 s (b) For VR = 0 V, Cj = Cjo = 0.org Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1 (c) fo = ⇒ f o = 8.90 = exp ⎜ D ⎟ − 1 ⎣ ⎝ VT ⎠ ⎦ ⎝ VT ⎠ ⎛V ⎞ exp ⎜ D ⎟ = 1 − 0.10 ⎝ VT ⎠ VD = VT ln ( 0.2 ⎞ ⎢ exp ⎜ ⎟ − 1⎥ exp ⎜ ⎟ −1 IF IS ⎣ ⎝ VT ⎠ ⎦ ⎝ 0.026 ⎠ = ⋅ = IR IS ⎡ ⎛ VR ⎞ ⎤ exp ⎛ −0.026 ⎠ ⎣ ⎝ VT ⎠ ⎦ 2190 = −1 IF = 2190 IR ______________________________________________________________________________________ ⎡ ⎛V ⎞ ⎤ 1.026 ⎠ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ (iv) ( ) ⎡ ⎛ − 0.28 V D = VT ln⎜⎜ D ⎟⎟ ⎝ IS ⎠ ⎛ 10 × 10 −6 ⎞ (a) (i) V D = (0.42 ×10 −9 ______________________________________________________________________________________ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1. ID2 ⎛ V − VD1 ⎞ = 10 = exp ⎜ D 2 ⎟ I D1 ⎝ VT ⎠ ΔVD = VT ln (10) ⇒ ΔVD = 59. ΔVD = VT ln (100 ) ⇒ ΔVD = 119.org Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1.33 ⎛I ⎞ ⎛ 2 × 10−3 ⎞ VD = Vt ln ⎜ D ⎟ = (0.20 V, I D = −5 × 10 −24 A For V D = −2 V, I D = −5 × 10 −24 A ______________________________________________________________________________________ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1.36 IS doubles for every 5C increase in temperature.64 Where n equals number of 5C increases.026 ⎠ By trial and error, V D = 0.8 V ______________________________________________________________________________________ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1.39 ⎛ I ⎞ 10 = I D ( 2 × 10 4 ) + VD and VD = ( 0.026 ) ln ⎜ D−12 ⎟ ⎝ 10 ⎠ Trial and error.45 = I D RTH + VD , VD = VT ln ⎜ D ⎟ ⎝ IS ⎠ By trial and error: I D = 2.org Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1.927 V Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ ______________________________________________________________________________________ 1.43 (a) Assume diode is conducting.7 μ A (b) Let R1 = 50 k Ω Diode is cutoff.44 At node VA: 5 − VA V (1) = ID + A 2 2 At node V B = V A − Vγ 5 − (VA − Vr ) (VA − Vr ) (2) + ID = 2 2 5 − (VA − Vr ) ⎡ 5 − VA VA ⎤ VA − Vr So +⎢ − ⎥= 3 ⎣ 2 2⎦ 2 Multiply by 6: 10 − 2 (VA − Vr ) + 15 − 6VA = 3 (VA − Vr ) 25 + 2Vr + 3Vr = 11VA (a) Vr = 0.545 V Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 5 − VA VA From (1) I D = − = 2.46 Minimum diode current for VPS (min) I D (min) = 2 mA, VD = 0.org Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 2 − 0.026 ⎠ By trial and error, V D = VO = 0.49 (a) Diode forward biased VD = 0.30 mA VI − 2Vr − V0 5 − 3(0.51 Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ V (0.05 I DQ = 50 μ A peak-to-peak vd = idτ d = (26)(50) μ A ⇒ vd = 1.30 mV peak-to-peak (0.05 I DQ = 5 μ A peak-to-peak vd = idτ d = (260)(5) μ V ⇒ vd = 1.30 mV peak-to-peak ______________________________________________________________________________________ 1. diode resistance rd = VT /I ⎛ ⎞ ⎛ rd ⎞ ⎜ VT /I ⎟ vd = ⎜ ⎟ vS = ⎜ V ⎟ vS ⎝ rd + RS ⎠ ⎜⎜ T + RS ⎟⎟ ⎝ I ⎠ ⎛ VT ⎞ vd = ⎜ ⎟ vs = vo ⎝ VT + IRS ⎠ b.0909 vS ⎝ VT + IRS ⎠ 0.26) vS ______________________________________________________________________________________ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ 1.54 pn junction diode ⎛ 0.55 ⎛V ⎞ Schottky: I ≅ I S exp ⎜ a ⎟ ⎝ VT ⎠ ⎛ I ⎞ ⎛ 0.5 × 10−3 ⎞ Va = VT ln ⎜ ⎟ = (0.1796 V Then Va of pn junction = 0.4796 ⎞ exp ⎜ a ⎟ exp ⎜ ⎟ ⎝ VT ⎠ ⎝ 0.org Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ I1 + I 2 = 0.49999 mA pn junction, I1 = 0.00001 mA (b) ⎛V ⎞ ⎛V ⎞ I = 10 −12 exp ⎜ D1 ⎟ = 5 × 10−8 exp ⎜ D 2 ⎟ ⎝ VT ⎠ ⎝ VT ⎠ VD1 + VD 2 = 0.9 − VD1 ⎞ 10−12 exp ⎜ D1 ⎟ = 5 × 10−8 exp ⎜ ⎟ ⎝ VT ⎠ ⎝ VT ⎠ ⎛ 0.9 ⎞ ⎛ −VD1 ⎞ = 5 ×10−8 exp ⎜ ⎟ exp ⎜ ⎟ ⎝ T ⎠ V ⎝ VT ⎠ ⎛ 2V ⎞ ⎛ 5 × 10−8 ⎞ ⎛ 0.026 ⎠ ⎛ 5 × 10−8 ⎞ 2VD1 = VT ln ⎜ −12 ⎟ + 0.5907 pn junction VD 2 = 0.1 mA rZ = 10Ω Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ I Z rZ = ( 0.01 VZ = VZ 0 + I Z rZ = 5. I = IZ + IL V V − V0 V − VZ 0 I L = 0 , I = PS , IZ = 0 RL R rZ 10 − V0 V0 − 5.02 Microelectronics: Circuit Analysis and Design, 4th edition Chapter 1 By D. Neamen Problem Solutions ______________________________________________________________________________________ V0 = VZ = VZ 0 + I Z rZ = 6.60 For VD = 0, I SC = 0.2 ⎞ For ID = 0 VD = VT ln ⎜ −14 + 1⎟ ⎝ 5 × 10 ⎠ VD = VDC = 0.org Microelectronics: Circuit Analysis and Design, 4th edition Chapter 2 By D. Neamen Problem Solutions ______________________________________________________________________________________ Chapter 2 2.9809π rad Now T 2π 1 1 υ O (avg ) = ∫ υ O (t )dt = [10 sin x − 0.2 v0 = vI − vD ⎛i ⎞ v vD = VT ln ⎜ D ⎟ and iD = 0 ⎝ S⎠ I R ⎛ v ⎞ v0 = vI − VT ln ⎜ 0 ⎟ ⎝ IS R ⎠ ______________________________________________________________________________________ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 2 By D. Neamen Problem Solutions ______________________________________________________________________________________ 2.6% ⎝ 360 ⎠ ______________________________________________________________________________________ Microelectronics: Circuit Analysis and Design, 4th edition Chapter 2 By D.