HSMS-280C Datasheet, PDF (3/10 Pages) Broadcom Corporation. – Surface Mount RF Schottky Barrier Diodes

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. Avago 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.
In a quad, the diagonal capacitance is the capacitance
between points A and B as shown in the figure below.
The diagonal capacitance is calculated using the follow-
ing formula
C_DIAGONAL = __C_1_x__C_2 + ___C_3_x_C_4
C₁ + C₂ C₃ + C₄
A
C₁
C₃
C
C₂
C₄
B
The equivalent adjacent capacitance is the capacitance
between points A and C in the figure below. This capaci-
tance is calculated using the following formula
C_ADJACENT = C₁ + _______1_____
–1– + –1– + –1–
C₂ C₃ C₄
This information does not apply to cross-over quad
diodes.
Linear Equivalent Circuit, Diode Chip
R_j
R_S
C_j
R_S = series resistance (see Table of SPICE parameters)
C _j = junction capacitance (see Table of SPICE parameters)
R_j =
8.33 X 10^-5 nT
I_b + I_s
where
I_b = externally applied bias current in amps
I_s = saturation current (see table of SPICE parameters)
T = temperature, K
n = ideality factor (see table of SPICE parameters)
Note:
To effectively model the packaged HSMS-280x product,
please refer to Application Note AN1124.
SPICE Parameters
Parameter Units
B_V
V
C_J0
pF
E_G
eV
I_BV
A
I_S
A
N
R_S
Ω
P_B
V
P_T
M
HSMS-280x
75
1.6
0.69
E-5
3.00E-08
1.08
30
0.65
2
0.5
3