HSMS-281X HP [Agilent(Hewlett-Packard)], HSMS-281X Datasheet - Page 3

• Manufacturer Part Number: HSMS-281X
• Description: Surface Mount RF Schottky Barrier Diodes
• Manufacturer: HP [Agilent(Hewlett-Packard)]

Quad Capacitance
Capacitance of Schottky diode
quads is measured using an
HP4271 LCR meter. This
instrument effectively isolates
individual diode branches from
the others, allowing accurate
capacitance measurement of each
branch or each diode. The
conditions are: 20 mV R.M.S.
voltage at 1 MHz. Agilent defines
this measurement as “CM”, and it
is equivalent to the capacitance of
the diode by itself. The equivalent
diagonal and adjacent
capacitances can then be
calculated by the formulas given
below.
Linear Equivalent Circuit, Diode Chip
R
C
R
where
I
I
T = temperature, °K
n = ideality factor (see table of SPICE parameters)
Note:
To effectively model the packaged HSMS-281x product,
please refer to Application Note AN1124.
b
s
S
j
j
= externally applied bias current in amps
= saturation current (see table of SPICE parameters)
=
= junction capacitance (see Table of SPICE parameters)
= series resistance (see Table of SPICE parameters)
8.33 X 10
R
I
S
b
+ I
s
-5
nT
R
C
j
j
In a quad, the diagonal capaci-
tance is the capacitance between
points A and B as shown in the
figure below. The diagonal
capacitance is calculated using
the following formula
C
C
DIAGONAL
C
C
1
2
= _______ + _______
C
C
1
1
+ C
x C
2
2
C
C
3
4
C
C
3
3
+ C
x C
4
4
A
B
SPICE Parameters
Parameter Units HSMS-281x
The equivalent adjacent
capacitance is the capacitance
between points A and C in the
figure below. This capacitance is
calculated using the following
formula
C
C
I
B
E
P
R
P
M
I
N
BV
ADJACENT
J0
S
G
B
V
T
S
3
= C
pF
eV
Ω
V
A
A
V
1
+ ____________
–– + –– + ––
C
1
2
4.8E - 9
0.69
1.08
0.65
E - 5
1.1
0.5
25
10
1
1
C
2
3
C
1
4