fundamentals of engineering supplied-reference handbook - Ventech!

OPERATIONAL AMPLIFIERS
Ideal
v2 vo = A(v1 – v2)
where
v
1
A is large (> 10 4 ), and
v1 – v2 is small enough so as not to saturate the amplifier.
For the ideal operational amplifier, assume that the input
currents are zero and that the gain A is infinite so when
operating linearly v2 – v1 = 0.
For the two-source configuration with an ideal operational
amplifier,
va
R 1
R 2
v
b
vo
R2
⎛ R ⎞
vo
va
vb
R ⎜ 2
= − + 1 +
R ⎟
1 ⎝ 1 ⎠
If va = 0, we have a non-inverting amplifier with
⎛ R ⎞
vo
⎜ 2 = 1 + vb
R ⎟
⎝ 1 ⎠
If vb = 0, we have an inverting amplifier with
R2
vo
= − va
R
1
SOLID-STATE ELECTRONICS AND DEVICES
Conductivity of a semiconductor material:
σ = q (nµn + pµp), where
µn ≡ electron mobility,
µp ≡ hole mobility,
n ≡ electron concentration,
p ≡ hole concentration, and
−19
q ≡ charge on an electron ( 1.6× 10 C ).
Doped material:
p-type material; pp ≈ Na
n-type material; nn ≈ Nd
Carrier concentrations at equilibrium
(p)(n) = ni 2 , where
ni ≡ intrinsic concentration.
vo
182
ELECTRICAL AND COMPUTER ENGINEERING (continued)
Built-in potential (contact potential) of a p-n junction:
Thermal voltage
kT N N
V 0 = ln
q
V
T
a d
2
ni
kT
= ≈ 0.026V at 300 ° K
q
Na = acceptor concentration,
Nd = donor concentration,
T = temperature (K), and
k = Boltzmann's Constant = 1.38 × 10 –23 J /K
Capacitance of abrupt p – n junction diode
( V ) Co
V Vbi
C = 1 − , where
Co = junction capacitance at V = 0,
V = potential of anode with respect to cathode, and
Vbi = junction contact potential.
Resistance of a diffused layer is
R = Rs (L/W), where
Rs = sheet resistance = ρ/d in ohms per square
ρ = resistivity,
d = thickness,
L = length of diffusion, and
W = width of diffusion.
TABULATED CHARACTERISTICS FOR:
Diodes
Bipolar Junction Transistor (BJT)
N-Channel JFET and MOSFET
Enhancement MOSFETs
are on the following pages.