課程名稱︰數位電子學
課程性質︰系必修
課程教師︰顧孟愷
開課學院：電資學院
開課系所︰資工系
考試日期（年月日）︰2010.4.26
考試時限（分鐘）：180
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
Digital Electronics Midterm
Instructor: Mong-Kai Ku
4/26/2010
Grading: Total 100 points
1.
--------+Vcc-----------
| | Amplification
| |
↓ I1 ↓I2 PTAT voltage generator→Amplification→A/Dconverter
| | →Digital scaling and offset
| | →Display
↓ ↓
_ _
| |
_______________________
|
_(ground)
-
(a)(10%)Please mark the two points for(mark for correct polarity) voltage
proportional to absolute temperature in the above figure and derive the
equation for PTAT voltage.
(b)Assume VFS = 1.0V for A/D converter, I1 = 10I2, and we want to measure from
0K to 600K.
(1)(5%)What is amplification factor A to fully utilize the A/D converter?
(2)(5%)What is the accuracy of this thermometer?
2.(10%)Use current and voltage division to find I1,I2 and V3 in the current in
Fig.1 if I = 5mA, R1 = 2.4kΩ, R2 = 5.6Ω, R3 = 3.6Ω
---------------I2→-----------
| | |
| ↓I1 R2
↑I R1 R3 +
| | | V3
----------------------------- -
Fig.1
3.(10%)Draw a two-dimensional conceptual pecture of the silicon lattice
containing one donor atom and two acceptor atom in adjacent lattice positions
. Are there any free electrons or hole?
4.
(a)(10%)At what temperature will ni = 10^13/cm^3 in silicon?
(b)(10%)A silicon wafer is uniformly doped with 5.5 x 10^16 phosphorus
atoms/cm^3 and 4.5 x 10^16 boron atoms/cm^3. Find the electron and hole
concentrations, the electron and hole mobilities, and the resistivity of
this silicon material at 300K. Is this material n- or p-type?
Temperature(K) 500 333 250 200
Intrinsic carrier density(cm^-6)
10^16
10^14 Germanium
10^12
10^10
10^8 Silicon
10^6
10^2 Gallium arsenide
10^0
Reciprocal temperature(1000/T) 2 3 4 5
B(K^-3xcm^-6) EG(eV)
Si 1.08x10^31 1.12
Ge 2.31x10^30 0.66
GaAs 1.27x10^29 1.42
5.(20%)What is maximum load current IL that can be drawn from the Zener
regulator in Fig.5 if it is to maintain a regulated output? What is the
minimum value of RL that can be used and still have a regulated output
voltage?
-----15kΩ--------→IL-----------
| | |
+ ↑(Zener) | VZ = 9V
27V | RL RZ = 0
- | |
| | |
---------------------------------
Figure 5
6.(20%)Find the Q-point for the diodes in the circuits in Fig.6 using the
constant voltage drop model with Von = 0.6 V.
0V
↓
|
+10V--→--3.3kΩ-----6.8kΩ------------2.4kΩ---- -5V
|
↑
|
+5V
Figure 6
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 59.112.80.222
※ 編輯: oscarchichun 來自: 59.112.80.222 (06/29 01:24)