5
Applications Information
Introduction —
Product Selection
Agilent’s family of Schottky
products provides unique solu-
tions to many design problems.
The first step in choosing the right
product is to select the diode type.
All of the products in the
HSMS-280x family use the same
diode chip, and the same is true of
the HSMS-281x and HSMS-282x
families. Each family has a
different set of characteristics
which can be compared most
easily by consulting the SPICE
parameters in Table 1.
A review of these data shows that
the HSMS-280x family has the
highest breakdown voltage, but at
the expense of a high value of
series resistance (R
s
). In applica-
tions which do not require high
voltage the HSMS-282x family,
with a lower value of series
resistance, will offer higher
current carrying capacity and
better performance. The HSMS-
281x family is a hybrid Schottky
(as is the HSMS-280x), offering
lower 1/f or flicker noise than the
HSMS-282x family.
In general, the HSMS-282x family
should be the designer’s first
choice, with the -280x family
reserved for high voltage applica-
tions and the HSMS-281x family
for low flicker noise applications.
0.026
0.07
0.035
0.016
Figure 6. PCB Pad Layout
(dimensions in inches).
Assembly Instructions
SOT-363 PCB Footprint
A recommended PCB pad layout
for the miniature SOT-363 (SC-70,
6 lead) package is shown in
Figure 7 (dimensions are in
inches). This layout provides
ample allowance for package
placement by automated assembly
equipment without adding
parasitics that could impair the
performance.
0.026
Assembly Instructions
SOT-323 PCB Footprint
A recommended PCB pad layout
for the miniature SOT-323 (SC-70)
package is shown in Figure 6
(dimensions are in inches). This
layout provides ample allowance
for package placement by auto-
mated assembly equipment
without adding parasitics that
could impair the performance.
Table 1. Typical SPICE Parameters.
Parameter
B
V
C
J0
E
G
I
BV
I
S
N
R
S
P
B
(V
J
)
P
T
(XTI)
M
Units
V
pF
eV
A
A
Ω
V
HSMS-280x
75
1.6
0.69
1 E-5
3 E-8
1.08
30
0.65
2
0.5
HSMS-281x
25
1.1
0.69
1 E-5
4.8 E-9
1.08
10
0.65
2
0.5
HSMS-282x
0.075
15
0.7
0.69
1 E-4
2.2 E-8
1.08
6.0
0.65
2
0.5
0.035
0.016
Figure 7. PCB Pad Layout
(dimensions in inches).
AGILENT [ AGILENT TECHNOLOGIES, LTD. ]
