mpc8641 Freescale Semiconductor, Inc, mpc8641 Datasheet - Page 116

• Manufacturer Part Number: mpc8641
• Description: Integrated Host Processor Hardware Specifications
• Manufacturer: Freescale Semiconductor, Inc

Thermal
Ideality factor is defined as the deviation from the ideal diode equation:
Another useful equation is:
Where:
The ratio of I
Solving for T, the equation becomes:
116
V
V
nT =
I
I
V
V
V
V
I
I
q = Charge of electron (1.6 x 10
n = Ideality factor (normally 1.0)
K = Boltzman’s constant (1.38 x 10
T = Temperature (Kelvins)
H
H
fw
s
H
L
d
f
H
L
– V
I
= Smaller diode bias current
fw
– V
= Saturation current
= Larger diode bias current
= Voltage forward biased
= Voltage at diode
= Forward current
= Diode voltage while I
= Diode voltage while I
L
= I
= 1.986 × 10
L
H
__________
1.986 × 10
= n
MPC8641 and MPC8641D Integrated Host Processor Hardware Specifications, Rev. 2
s
to I
V
H
L
e
KT
__
– V
q
is usually selected to be 10:1. The above simplifies to the following:
___
nKT
qV
L
ln
f
–4
–4
__
– 1
I
× nT
I
L
H
L
H
is flowing
is flowing
–19
–23
C)
Joules/K)
Freescale Semiconductor