課程名稱︰電子學一
課程性質︰必修
課程教師︰呂良鴻
開課學院：電機資訊學院
開課系所︰電機工程學系
考試日期（年月日）︰104/1/15
考試時限（分鐘）：110分鐘
試題 :
1031 Microeletronic Circuits I (Final)
date: 2015/01/15 (Thur)
time: 15:30 ~ 17:20
1. [10%] For β = 100, design the circuit shown in Fig. 1 so that the bias
currents in Q1, Q2, and Q3 are 2 mA, 2 mA, and 4 mA, respectively. Find the
values of V2, V3, V4, V5, V6, and V7. Assume all transistors operate in the
edge of active mode.
2. Consider the amplifier configuration of Fig. 2. It is required that the
amplifier input resistance (R_in) match the signal source resistance (R_sig)
of 100 Ω. Assume the amplifier is designed to operate at the largest
possible voltage gain (v_o/v_sig) and largest possible output signal
(v_o,max) and still satisfy the small-signal linear operation (i.e. |v_be|
≦ 10 mV) in active mode. Assume the transistor has β of 100.
(a) [2%] What is the value of R_E?
(b) [4%] Draw the small-signal model and label the value and polarity
correctly.
(c) [9%] Find the value of R_C and v_sig so that the amplifier satisfies the
design requirement.
3. Consider the circuit as shown in Fig. 3 where V_CC 10 V, R_C = 10 kΩ,
R_B = 100 kΩ, β = 100 for the BJT and the capacitors are rather large.
(a) [10%] As V_BB increases from 0 V to V_CC, sketch I_C and I_B versus
V_BB. Find the value of V_BB when the BJT operates at the edge of
saturation (EOS).
(b) [5%] Find the value of bias voltage V_BB to obtain a voltage gain
(v_o/v_i) of -100 V/V.
(c) [10%] If an output sinusoidal with an amplitude of 1V is required at
v_o, find the maximum voltage gain (v_o/v_i) and the value of bias
voltage V_BB.
4. Consider a CMOS process for which L _min = 0.5 μm, t_ox = 10 nm, μ_n =
550 cm^2/V.s, and V_t = 0.5 V. (The permittivity of the silicon dioxide is
3.45 x 10^-11 F/m)
(a) [10%] Find C_ox and k'_n. (units must be included in the answers)
(b) [10%] For an NMOSFET with W/L = 15 μm/0.5 μm, calculate the values of
V_ov and V_DSmin (minimum V_DS) to operate the transistor in saturation
region with a dc current I_D 100 μA.
(c) [5%] For the transistor in (b), find the value of V_GS required to cause
the transistor to operate as a 1000-Ω resistor for a very small V_DS.
5. (a) [8%] Fig. 4 shows a current mirror. Assume Vt = 1V, λ = 0, μ_n C_ox =
50μA/V^2. For Q1, Q2, and Q3 are the same as L = μm and W = 10μm. Please
obtain I3. (Hints: both Q1 and Q2 should be saturated to have a functional
current mirror.)
(b) Fig. 5 shows a common-source amplifier biased by a current mirror
*Please be aware of that the number obtained in (a) CAN NOT be plugged
into (b)*
(b-1) [2%] please point out which MOSFET performs the function of a voltage
amplifier ;
(b-2) [5%] Please draw the small signal model of the amplifier MOSFET with
its biasing MOSFET. ;
(b-3) [5%] Please find R1/R2 to bias the circuit at the on-set of cut-off
and saturation. ;
(b-4) [5%] Please find v_o/v_i and R_out.
http://ppt.cc/kFnK
http://ppt.cc/EVGi
http://ppt.cc/9Jr-
http://ppt.cc/ixDm
http://ppt.cc/-wih