1
Surface Mount RF Schottky
Barrier Diodes
Technical Data
HSMS-282x Series
Features
• Low Turn-On Voltage
(As Low as 0.34 V at 1 mA)
• Low FIT (Failure in Time)
Rate*
• Six-sigma Quality Level
• Single, Dual and Quad
Versions
• Unique Configurations in
Surface Mount SOT-363
Package
– increase flexibility
– save board space
– reduce cost
• HSMS-282K Grounded
Center Leads Provide up to
10 dB Higher Isolation
• Matched Diodes for
Consistent Performance
• Better Thermal Conductivity
for Higher Power Dissipation
* For more information see the
Surface Mount Schottky Reliability
Data Sheet.
Description/Applications
These Schottky diodes are
specifically designed for both
analog and digital applications.
This series offers a wide range of
specifications and package
configurations to give the
designer wide flexibility. Typical
applications of these Schottky
diodes are mixing, detecting,
switching, sampling, clamping,
and wave shaping. The
HSMS-282x series of diodes is the
Package Lead Code Identification, SOT-23/SOT-143
(Top View)
COMMON
CATHODE
#4
UNCONNECTED
PAIR
#5
COMMON
ANODE
#3
SERIES
#2
SINGLE
#0
12
3
12
34
RING
QUAD
#7
12
34
BRIDGE
QUAD
#8
12
34
CROSS-OVER
QUAD
#9
12
34
12
3
12
3
12
3
Package Lead Code
Identification, SOT-323
(Top View)
Package Lead Code
Identification, SOT-363
(Top View)
COMMON
CATHODE
F
COMMON
ANODE
E
SERIES
C
SINGLE
B
COMMON
CATHODE QUAD
M
UNCONNECTED
TRIO
L
BRIDGE
QUAD
P
COMMON
ANODE QUAD
N
RING
QUAD
R
123
654
HIGH ISOLATION
UNCONNECTED PAIR
K
123
654
123
654
123
654
123
654
123
654
best all-around choice for most
applications, featuring low series
resistance, low forward voltage at
all current levels and good RF
characteristics.
Note that Agilent’s manufacturing
techniques assure that dice found
in pairs and quads are taken from
adjacent sites on the wafer,
assuring the highest degree of
match.
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Electrical Specifications T
C
= 25
°
C, Single Diode
[4]
Maximum Maximum
Minimum Maximum Forward Reverse Typical
Part Package Breakdown Forward Voltage Leakage Maximum Dynamic
Number Marking Lead Voltage Voltage V
F
(V) @ I
R
(nA) @ Capacitance Resistance
HSMS
[5]
Code Code Configuration V
BR
(V) V
F
(mV) I
F
(mA) V
R
(V) C
T
(pF) R
D
(Ω)
[6]
2820 C0
[3]
0 Single 15 340 0.5 10 100 1 1.0 12
2822 C2
[3]
2 Series
2823 C3
[3]
3 Common Anode
2824 C4
[3]
4 Common Cathode
2825 C5
[3]
5 Unconnected Pair
2827 C7
[3]
7 Ring Quad
[5]
2828 C8
[3]
8 Bridge Quad
[5]
2829 C9
[3]
9 Cross-over Quad
282B C0
[7]
B Single
282C C2
[7]
C Series
282E C3
[7]
E Common Anode
282F C4
[7]
F Common Cathode
282K CK
[7]
K High Isolation
Unconnected Pair
282L CL
[7]
L Unconnected Trio
282M HH
[7]
M Common Cathode Quad
282N NN
[7]
N Common Anode Quad
282P CP
[7]
P Bridge Quad
282R OO
[7]
R Ring Quad
Test Conditions I
R
= 100 µAI
F
= 1 mA
[1]
V
F
= 0 V I
F
= 5 mA
f = 1 MHz
[2]
Notes:
1. ∆V
F
for diodes in pairs and quads in 15 mV maximum at 1 mA.
2. ∆C
TO
for diodes in pairs and quads is 0.2 pF maximum.
3. Package marking code is in white.
4. Effective Carrier Lifetime (τ) for all these diodes is 100 ps maximum measured with Krakauer method at 5 mA.
5. See section titled “Quad Capacitance.”
6. R
D
= R
S
+ 5.2Ω at 25°C and I
f
= 5 mA.
7. Package marking code is laser marked.
Absolute Maximum Ratings
[1]
T
C
= 25°C
Symbol Parameter Unit SOT-23/SOT-143 SOT-323/SOT-363
I
f
Forward Current (1 µs Pulse) Amp 1 1
P
IV
Peak Inverse Voltage V 15 15
T
j
Junction Temperature °C 150 150
T
stg
Storage Temperature °C -65 to 150 -65 to 150
θ
jc
Thermal Resistance
[2]
°C/W 500 150
Notes:
1. Operation in excess of any one of these conditions may result in permanent damage to
the device.
2. T
C
= +25°C, where T
C
is defined to be the temperature at the package pins where
contact is made to the circuit board.
Notes:
1. Package marking provides
orientation and identification.
2. See “Electrical Specifications” for
appropriate package marking.
Pin Connections and
Package Marking
GUx
1
2
3
6
5
4
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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.
v
oltage 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 capaci-
tances can then be calculated by
the formulas given below.
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
1
x C
2
C
3
x C
4
C
DIAGONAL
= _______ + _______
C
1
+ C
2
C
3
+ C
4
C
1
C
2
C
4
C
3
A
B
C
The equivalent adjacent
capacitance is the capacitance
between points A and C in the
figure below. This capacitance is
calculated using the following
formula
1
C
ADJACENT
= C
1
+ ____________
1 1 1
–– + –– + ––
C
2
C
3
C
4
This information does not apply
to cross-over quad diodes.
SPICE Parameters
Parameter Units HSMS-282x
B
V
V15
C
J0
pF 0.7
E
G
eV 0.69
I
BV
A1E-4
I
S
A 2.2E-8
N 1.08
R
S
Ω6.0
P
B
V 0.65
P
T
2
M 0.5
C
j
R
j
R
S
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-282x product,
please refer to Application Note AN1124.
R
S
= series resistance (see Table of SPICE parameters)
C
j
= junction capacitance (see Table of SPICE parameters)
Linear Equivalent Circuit Model
Diode Chip
E
SD WARNING:
Handling Precautions Should Be Taken To Avoid Static Discharge.
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Typical Performance, T
C
= 25
°
C (unless otherwise noted), Single Diode
Figure 1. Forward Current vs.
Forward Voltage at Temperatures.
0 0.10 0.20 0.30 0.500.40
I
F
– FORWARD CURRENT (mA)
V
F
– FORWARD VOLTAGE (V)
0.01
10
1
0.1
100 T
A
= +125ϒC
T
A
= +75ϒC
T
A
= +25ϒC
T
A
= –25ϒC
Figure 2. Reverse Current vs.
Reverse Voltage at Temperatures.
05 15
I
R
– REVERSE CURRENT (nA)
V
R
– REVERSE VOLTAGE (V)
10
1
1000
100
10
100,000
10,000
T
A
= +125ϒC
T
A
= +75ϒC
T
A
= +25ϒC
Figure 3. Total Capacitance vs.
Reverse Voltage.
02 86
C
T
– CAPACITANCE (pF)
V
R
– REVERSE VOLTAGE (V)
4
0
0.6
0.4
0.2
1
0.8
Figure 4. Dynamic Resistance vs.
Forward Current.
0.1 1 100
R
D
– DYNAMIC RESISTANCE ()
I
F
– FORWARD CURRENT (mA)
10
1
10
1000
100
V
F
- FORWARD VOLTAGE (V)
Figure 5. Typical V
f
Match, Series Pairs
and Quads at Mixer Bias Levels.
30
10
1
0.3
30
10
1
0.3
I
F
- FORWARD CURRENT (mA)
∆V
F
- FORWARD VOLTAGE DIFFERENCE (mV)
0.2 0.4 0.6 0.8 1.0 1.2 1.4
I
F
(Left Scale)
∆
V
F
(Right Scale)
V
F
- FORWARD VOLTAGE (V)
Figure 6. Typical V
f
Match, Series Pairs
at Detector Bias Levels.
100
10
1
1.0
0.1
I
F
- FORWARD CURRENT (µA)
∆V
F
- FORWARD VOLTAGE DIFFERENCE (mV)
0.10 0.15 0.20 0.25
I
F
(Left Scale)
∆
V
F
(Right Scale)
Figure 7. Typical Output Voltage vs.
Input Power, Small Signal Detector
Operating at 850 MHz.
-40 -30
18 nH
RF in
3.3 nH 100 pF 100 KΩ
HSMS-282B Vo
0
V
O
– OUTPUT VOLTAGE (V)
P
in
– INPUT POWER (dBm)
-10-20
0.001
0.01
1
0.1
-25°C
+25°C
+75°C
DC bias = 3
µ
A
Figure 8. Typical Output Voltage vs.
Input Power, Large Signal Detector
Operating at 915 MHz.
-20 -10
RF in
100 pF 4.7 KΩ
68 Ω
HSMS-282B Vo
30
V
O
– OUTPUT VOLTAGE (V)
P
in
– INPUT POWER (dBm)
10 200
1E-005
0.0001
0.001
10
0.1
1
0.01
+25°C
LOCAL OSCILLATOR POWER (dBm)
Figure 9. Typical Conversion Loss vs.
L.O. Drive, 2.0 GHz (Ref AN997).
CONVERSION LOSS (dB)
12
10
9
8
7
62068104
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A
pplications Information
Product Selection
A
gilent’s family of surface mount
Schottky diodes provide unique
solutions to many design prob-
lems. Each is optimized for
certain applications.
The first step in choosing the right
product is to select the diode type.
A
ll of the products in the
HSMS-282x family use the same
diode chip–they differ only in
package configuration. The same
is true of the HSMS-280x, -281x,
285x, -286x and -270x families.
Each family has a different set of
characteristics, which can be
compared most easily by consult-
ing the SPICE parameters given
on each data sheet.
The HSMS-282x family has been
optimized for use in RF applica-
tions, such as
✓DC biased small signal
detectors to 1.5 GHz.
✓Biased or unbiased large
signal detectors (AGC or
power monitors) to 4 GHz.
✓Mixers and frequency
multipliers to 6 GHz.
The other feature of the
HSMS-282x family is its
unit-to-unit and lot-to-lot consis-
tency. The silicon chip used in this
series has been designed to use
the fewest possible processing
steps to minimize variations in
diode characteristics. Statistical
data on the consistency of this
product, in terms of SPICE
parameters, is available from
A
gilent.
For those applications requiring
v
ery high breakdown voltage, use
the HSMS-280x family of diodes.
Turn to the HSMS-281x when you
need very low flicker noise. The
HSMS-285x is a family of zero bias
detector diodes for small signal
applications. For high frequency
detector or mixer applications,
use the HSMS-286x family. The
HSMS-270x is a series of specialty
diodes for ultra high speed
clipping and clamping in digital
circuits.
Schottky Barrier Diode
Characteristics
Stripped of its package, a
Schottky barrier diode chip
consists of a metal-semiconductor
barrier formed by deposition of a
metal layer on a semiconductor.
The most common of several
different types, the passivated
diode, is shown in Figure 10,
along with its equivalent circuit.
RS is the parasitic series resis-
tance of the diode, the sum of the
bondwire and leadframe resis-
tance, the resistance of the bulk
layer of silicon, etc. RF energy
coupled into RS is lost as heat—it
does not contribute to the recti-
fied output of the diode. CJ is
parasitic junction capacitance of
the diode, controlled by the thick-
ness of the epitaxial layer and the
diameter of the Schottky contact.
Rj is the junction resistance of the
diode, a function of the total
current flowing through it.
R
S
R
j
C
j
METAL
SCHOTTKY JUNCTION
PASSIVATION PASSIVATION
N-TYPE OR P-TYPE EPI LAYER
N-TYPE OR P-TYPE SILICON SUBSTRATE
CROSS-SECTION OF SCHOTTKY
BARRIER DIODE CHIP EQUIVALENT
CIRCUIT
8.33 X 10-5 nT
Rj = –––––––––––– = RV – Rs
I
S + Ib
0.026
≈ ––––– at 25°C
IS + Ib
where
n = ideality factor (see table of
SPICE parameters)
T = temperature in °K
IS = saturation current (see
table of SPICE parameters)
Ib = externally applied bias
current in amps
Rv = sum of junction and series
resistance, the slope of the
V-I curve
IS is a function of diode barrier
height, and can range from
picoamps for high barrier diodes
to as much as 5 µA for very low
barrier diodes.
The Height of the Schottky
Barrier
The current-voltage characteristic
of a Schottky barrier diode at
room temperature is described by
the following equation:
V - IR
S
I = IS (e –––––– 1)
0.026
On a semi-log plot (as shown in
the Agilent catalog) the current
graph will be a straight line with
inverse slope 2.3 X 0.026 = 0.060
volts per cycle (until the effect of
Figure 10. Schottky Diode Chip.
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R
S
is seen in a curve that droops
at high current). All Schottky
diode curves have the same slope,
but not necessarily the same
v
alue of current for a given
v
oltage. This is determined by the
saturation current, I
S
, and is
related to the barrier height of the
diode.
Through the choice of p-type or
n-type silicon, and the selection
of metal, one can tailor the
characteristics of a Schottky
diode. Barrier height will be
altered, and at the same time C
J
and R
S
will be changed. In
general, very low barrier height
diodes (with high values of I
S
,
suitable for zero bias applica-
tions) are realized on p-type
silicon. Such diodes suffer from
higher values of R
S
than do the
n-type. Thus, p-type diodes are
generally reserved for detector
applications (where very high
v
alues of R
V
swamp out high R
S
)
and n-type diodes such as the
HSMS-282x are used for mixer
applications (where high L.O.
drive levels keep R
V
low). DC
biased detectors and self-biased
detectors used in gain or power
control circuits.
Detector Applications
Detector circuits can be divided
into two types, large signal
(P
in
> -20 dBm) and small signal
(P
in
< -20 dBm). In general, the
former use resistive impedance
matching at the input to improve
flatness over frequency—this is
possible since the input signal
levels are high enough to produce
adequate output voltages without
the need for a high Q reactive
input matching network. These
circuits are self-biased (no
external DC bias) and are used
for gain and power control of
amplifiers.
Small signal detectors are used as
very low cost receivers, and
require a reactive input imped-
ance matching network to
achieve adequate sensitivity and
output voltage. Those operating
with zero bias utilize the HSMS-
285x family of detector diodes.
However, superior performance
over temperature can be achieved
with the use of 3 to 30 µA of DC
bias. Such circuits will use the
HSMS-282x family of diodes if the
operating frequency is 1.5 GHz or
lower.
Typical performance of single
diode detectors (using
HSMS-2820 or HSMS-282B) can
be seen in the transfer curves
given in Figures 7 and 8. Such
detectors can be realized either
as series or shunt circuits, as
shown in Figure 11.
DC Bias
Shunt inductor provides
video signal return
Shunt diode provides
video signal return
DC Bias
DC Biased DiodesZero Biased Diodes
Figure 11. Single Diode Detectors.
The series and shunt circuits can
be combined into a voltage
doubler
[1]
, as shown in Figure 12.
The doubler offers three advan-
tages over the single diode
circuit.
✓The two diodes are in parallel
in the RF circuit, lowering the
input impedance and making
the design of the RF matching
network easier.
✓The two diodes are in series
in the output (video) circuit,
doubling the output voltage.
✓Some cancellation of
even-order harmonics takes
place at the input.
DC Bias
DC Biased DiodesZero Biased Diodes
Figure 12. Voltage Doubler.
The most compact and lowest
cost form of the doubler is
achieved when the HSMS-2822 or
HSMS-282C series pair is used.
Both the detection sensitivity and
the DC forward voltage of a
biased Schottky detector are
temperature sensitive. Where
both must be compensated over a
wide range of temperatures, the
differential detector
[2]
is often
used. Such a circuit requires that
the detector diode and the
reference diode exhibit identical
characteristics at all DC bias
levels and at all temperatures.
This is accomplished through the
use of two diodes in one package,
for example the HSMS-2825 in
Figure 13. In the Agilent assembly
facility, the two dice in a surface
mount package are taken from
adjacent sites on the wafer (as
illustrated in Figure 14). This
[1] Agilent Application Note 956-4, “Schottky Diode Voltage Doubler.”
[2] Raymond W. Waugh, “Designing Large-Signal Detectors for Handsets and Base
Stations,” Wireless Systems Design, Vol. 2, No. 7, July 1997, pp 42 – 48.
88759/02-5.PM6.0J 2001.04.25, 6:41 PMPage 6 AdobePageMaker6.0J/PPC
7
assures that the characteristics of
the two diodes are more highly
matched than would be possible
through individual testing and
hand matching.
matching
network
differential
amplifier
HSMS-2825
bias
Figure 13. Differential Detector.
Figure 14. Fabrication of Agilent
Diode Pairs.
In high power applications,
coupling of RF energy from the
detector diode to the reference
diode can introduce error in the
differential detector. The
HSMS-282K diode pair, in the six
lead SOT-363 package, has a
copper bar between the diodes
that adds 10 dB of additional
isolation between them. As this
part is manufactured in the
SOT-363 package it also provides
the benefit of being 40% smaller
than larger SOT-143 devices. The
HSMS-282K is illustrated in
Figure 15—note that the ground
connections must be made as
close to the package as possible
to minimize stray inductance to
ground.
PA detector diode
reference diode
to differential amplifier
V
bias
HSMS-282K
Figure 15. High Power Differential
Detector.
The concept of the voltage
doubler can be applied to the
differential detector, permitting
twice the output voltage for a
given input power (as well as
improving input impedance and
suppressing second harmonics).
However, care must be taken to
assure that the two reference
diodes closely match the two
detector diodes. One possible
configuration is given in Fig-
ure 16, using two HSMS-2825.
Board space can be saved
through the use of the HSMS-282P
open bridge quad, as shown in
Figure 17.
matching
network
differential
amplifier
HSMS-2825
HSMS-2825
bias
Figure 16. Voltage Doubler
Differential Detector.
differential
amplifier
HSMS-282P
bias
matching
network
Figure 17. Voltage Doubler
Differential Detector.
While the differential detector
works well over temperature,
another design approach
[3]
works
well for large signal detectors.
See Figure 18 for the schematic
and a physical layout of the
circuit. In this design, the two
4.7 KΩ resistors and diode D2 act
as a variable power divider,
assuring constant output voltage
over temperature and improving
output linearity.
V
o
D1
33 pF
HSMS-2825
or
HSMS-282K HSMS-282K
4.7 KΩ
33 pF
4.7 KΩ
4.7 KΩ
D2
68 Ω
68 Ω
RF
in
RF
in
V
o
Figure 18. Temperature Compensated
Detector.
In certain applications, such as a
dual-band cellphone handset
operating at both 900 and
1800 MHz, the second harmonics
generated in the power control
output detector when the handset
is working at 900 MHz can cause
problems. A filter at the output
can reduce unwanted emissions
at 1800 MHz in this case, but a
[3]
Hans Eriksson and Raymond W. Waugh, “A Temperature Compensated Linear Diode
Detector,” to be published.
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8
lower cost solution is available[4].
Illustrated schematically in
Figure 19, this circuit uses diode
D2 and its associated passive
components to cancel all even
order harmonics at the detector’s
RF input. Diodes D3 and D4
provide temperature compensa-
tion as described above. All four
diodes are contained in a single
HSMS- 282R package, as illus-
trated in the layout shown in
Figure 20.
RF in D1 R1 V+
R2
D3
C1V–
R4
D4
C1 = C2 ≈ 100 pF
R1 = R2 = R3 = R4 = 4.7 KΩ
D1 & D2 & D3 & D4 = HSMS-282R
C2
D2
68 ΩR3
Figure 19. Schematic of Suppressed
Harmonic Detector.
HSMS-282R
4.7 KΩ4.7 KΩ
100 pF
100 pF
68 Ω
V–
RF in
V+
Figure 20. Layout of Suppressed
Harmonic Detector.
Note that the forgoing discussion
refers to the output voltage being
extracted at point V+ with respect
to ground. If a differential output
is taken at V+ with respect to V-,
the circuit acts as a voltage
doubler.
Mixer applications
The HSMS-282x family, with its
wide variety of packaging, can be
used to make excellent mixers at
frequencies up to 6 GHz.
The HSMS-2827 ring quad of
matched diodes (in the SOT-143
package) has been designed for
double balanced mixers. The
smaller (SOT-363) HSMS-282R ring
quad can similarly be used, if the
quad is closed with external
connections as shown in Figure 21.
HSMS-282R
IF out
RF in
LO in
Figure 21. Double Balanced Mixer.
Both of these networks require a
crossover or a three dimensional
circuit. A planar mixer can be
made using the SOT-143 cross-
over quad, HSMS-2829, as shown
in Figure 22. In this product, a
special lead frame permits the
crossover to be placed inside the
plastic package itself, eliminating
the need for via holes (or other
measures) in the RF portion of
the circuit itself.
HSMS-2829
IF out
RF in
LO in
Figure 22. Planar Double Balanced
Mixer.
A review of Figure 21 may lead to
the question as to why the
HSMS-282R ring quad is open on
the ends. Distortion in double
balanced mixers can be reduced
if LO drive is increased, up to the
point where the Schottky diodes
are driven into saturation. Above
this point, increased LO drive will
not result in improvements in
distortion. The use of expensive
high barrier diodes (such as those
fabricated on GaAs) can take
advantage of higher LO drive
power, but a lower cost solution
is to use a eight (or twelve) diode
ring quad. The open design of the
HSMS-282R permits this to easily
be done, as shown in Figure 23.
HSMS-282R IF out
RF in
LO in
Figure 23. Low Distortion Double
Balanced Mixer.
This same technique can be used
in the single-balanced mixer.
Figure 24 shows such a mixer,
with two diodes in each spot
normally occupied by one. This
mixer, with a sufficiently high LO
drive level, will display low
distortion.
HSMS-282R
180°
hybrid IF out
LO in
RF in
Low pass
filter
Figure 24. Low Distortion Balanced
Mixer.
[4]
Alan Rixon and Raymond W. Waugh, “A Suppressed Harmonic Power Detector for Dual
Band ‘Phones,” to be published.
88759/02-5.PM6.0J 2001.04.25, 6:41 PMPage 8 AdobePageMaker6.0J/PPC
9
Sampling Applications
The six lead HSMS-282P can be
used in a sampling circuit, as
shown in Figure 25. As was the
case with the six lead HSMS-282R
in the mixer, the open bridge
quad is closed with traces on the
circuit board. The quad was not
closed internally so that it could
be used in other applications,
such as illustrated in Figure 17.
HSMS-282P
sampling
pulse
sample
point
sampling circuit
Figure 25. Sampling Circuit.
Thermal Considerations
The obvious advantage of the
SOT-323 and SOT-363 over the
SOT-23 and SOT-142 is combina-
tion of smaller size and extra
leads. However, the copper
leadframe in the SOT-3x3 has a
thermal conductivity four times
higher than the Alloy 42
leadframe of the SOT-23 and
SOT-143, which enables the
smaller packages to dissipate
more power.
The maximum junction tempera-
ture for these three families of
Schottky diodes is 150°C under
all operating conditions. The
following equation applies to the
thermal analysis of diodes:
Tj = (V
f
I
f
+ P
RF
) θ
jc
+ T
a
(1)
where
T
j
= junction temperature
T
a
= diode case temperature
θ
jc
= thermal resistance
V
f
I
f
= DC power dissipated
P
RF
= RF power dissipated
Note that θ
jc
, the thermal resis-
tance from diode junction to the
foot of the leads, is the sum of
two component resistances,
θ
jc
= θ
pkg
+ θ
chip
(2)
Package thermal resistance for
the SOT-3x3 package is approxi-
mately 100°C/W, and the chip
thermal resistance for the
HSMS-282x family of diodes is
approximately 40°C/W. The
designer will have to add in the
thermal resistance from diode
case to ambient—a poor choice
of circuit board material or heat
sink design can make this number
very high.
Equation (1) would be straightfor-
ward to solve but for the fact that
diode forward voltage is a func-
tion of temperature as well as
forward current. The equation for
V
f
is:
11600 (V
f
– I
f
R
s
)
nT (3)
I
f
= I
S
e – 1
where n = ideality factor
T = temperature in °K
R
s
= diode series resistance
and I
S
(diode saturation current)
is given by
2 1 1
n – 4060
(
T – 298
)
I
s
= I
0
(
T
)
e
298 (4)
Equation (4) is substituted into
equation (3), and equations (1)
and (3) are solved simultaneously
to obtain the value of junction
temperature for given values of
diode case temperature, DC
power dissipation and RF power
dissipation.
Diode Burnout
Any Schottky junction, be it an RF
diode or the gate of a MESFET, is
relatively delicate and can be
burned out with excessive RF
power. Many crystal video
receivers used in RFID (tag)
applications find themselves in
poorly controlled environments
where high power sources may be
present. Examples are the areas
around airport and FAA radars,
nearby ham radio operators, the
vicinity of a broadcast band
transmitter, etc. In such
environments, the Schottky
diodes of the receiver can be
protected by a device known as a
limiter diode.
[5]
Formerly
available only in radar warning
receivers and other high cost
electronic warfare applications,
these diodes have been adapted to
commercial and consumer
circuits.
Agilent offers a complete line of
surface mountable PIN limiter
diodes. Most notably, our HSMP-
4820 (SOT-23) can act as a very
fast (nanosecond) power-sensitive
switch when placed between the
antenna and the Schottky diode,
shorting out the RF circuit
temporarily and reflecting the
excessive RF energy back out the
antenna.
[5]
Agilent Application Note 1050, “Low
Cost, Surface Mount Power Limiters.”
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10
A
ssembly Instructions
SOT-3x3 PCB Footprint
Recommended PCB pad layouts
for the miniature SOT-3x3 (SC-70)
packages are shown in Figures 26
and 27 (dimensions are in inches).
These layouts provide ample
allowance for package placement
by automated assembly equipment
without adding parasitics that
could impair the performance.
0.026
0.035
0.07
0.016
Figure 26. PCB Pad Layout, SOT-323
(dimensions in inches).
0.026
0.075
0.016
0.035
Figure 27. PCB Pad Layout, SOT-363
(dimensions in inches).
TIME (seconds)
T
MAX
TEMPERATURE (°C)
0
0
50
100
150
200
250
60
Preheat
Zone Cool Down
Zone
Reflow
Zone
120 180 240 300
Figure 28. Surface Mount Assembly Profile.
SMT Assembly
Reliable assembly of surface
mount components is a complex
process that involves many
material, process, and equipment
factors, including: method of
heating (e.g., IR or vapor phase
reflow, wave soldering, etc.)
circuit board material, conductor
thickness and pattern, type of
solder alloy, and the thermal
conductivity and thermal mass of
components. Components with a
low mass, such as the SOT
packages, will reach solder reflow
temperatures faster than those
with a greater mass.
Agilent’s diodes have been
qualified to the time-temperature
profile shown in Figure 28. This
profile is representative of an IR
reflow type of surface mount
assembly process.
After ramping up from room
temperature, the circuit board
with components attached to it
(held in place with solder paste)
passes through one or more
preheat zones. The preheat zones
increase the temperature of the
board and components to prevent
thermal shock and begin evaporat-
ing solvents from the solder paste.
The reflow zone briefly elevates
the temperature sufficiently to
produce a reflow of the solder.
The rates of change of tempera-
ture for the ramp-up and cool-
down zones are chosen to be low
enough to not cause deformation
of the board or damage to compo-
nents due to thermal shock. The
maximum temperature in the
reflow zone (T
MAX
) should not
exceed 235°C.
These parameters are typical for a
surface mount assembly process
for Agilent diodes. As a general
guideline, the circuit board and
components should be exposed
only to the minimum tempera-
tures and times necessary to
achieve a uniform reflow of
solder.
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11
Package Dimensions
Outline 23 (SOT-23)
Outline 143 (SOT-143)
3
12
X X X
PACKAGE
MARKING
CODE (XX)
DATE CODE (X)
SIDE VIEW
TOP VIEW
END VIEW
THESE DIMENSIONS FOR HSMS-280X AND -281X FAMILIES ONLY.
DIMENSIONS ARE IN MILLIMETERS (INCHES)
1.02 (0.040)
0.89 (0.035)
1.03 (0.041)
0.89 (0.035)
0.60 (0.024)
0.45 (0.018)
1.40 (0.055)
1.20 (0.047) 2.65 (0.104)
2.10 (0.083)
3.06 (0.120)
2.80 (0.110)
2.04 (0.080)
1.78 (0.070)
2.05 (0.080)
1.78 (0.070)
1.04 (0.041)
0.85 (0.033)
0.152 (0.006)
0.086 (0.003)
0.180 (0.007)
0.085 (0.003)
0.10 (0.004)
0.013 (0.0005) 0.69 (0.027)
0.45 (0.018)
0.54 (0.021)
0.37 (0.015)
*
*
*
*
0.69 (0.027)
0.45 (0.018)
1.40 (0.055)
1.20 (0.047) 2.65 (0.104)
2.10 (0.083)
0.60 (0.024)
0.45 (0.018) 0.54 (0.021)
0.37 (0.015)
0.10 (0.004)
0.013 (0.0005)
1.04 (0.041)
0.85 (0.033)
0.92 (0.036)
0.78 (0.031)
2.04 (0.080)
1.78 (0.070)
DIMENSIONS ARE IN MILLIMETERS (INCHES)
0.15 (0.006)
0.09 (0.003)
3.06 (0.120)
2.80 (0.110)
PACKAGE
MARKING
CODE (XX)
BE
CE
X X X
DATE CODE (X)
Part Number Ordering Information
No. of
Part Number Devices Container
HSMS-282x-TR2* 10000 13" Reel
HSMS-282x-TR1* 3000 7" Reel
HSMS-282x-BLK * 100 antistatic bag
x = 0, 2, 3, 4, 5, 7, 8, 9, B, C, E, F, K, L, M, N, P or R
Outline SOT-363 (SC-70 6 Lead)
Outline SOT-323 (SC-70 3 Lead)
2.20 (0.087)
2.00 (0.079) 1.35 (0.053)
1.15 (0.045)
1.30 (0.051)
REF.
0.650 BSC (0.025)
2.20 (0.087)
1.80 (0.071)
0.10 (0.004)
0.00 (0.00)
0.25 (0.010)
0.15 (0.006)
1.00 (0.039)
0.80 (0.031) 0.20 (0.008)
0.10 (0.004)
0.30 (0.012)
0.10 (0.004)
0.30 REF.
10
°
0.425 (0.017)
TYP.
DIMENSIONS ARE IN MILLIMETERS (INCHES)
PACKAGE
MARKING
CODE (XX)
X X X
DATE CODE (X)
2.20 (0.087)
2.00 (0.079) 1.35 (0.053)
1.15 (0.045)
1.30 (0.051)
REF.
0.650 BSC (0.025)
2.20 (0.087)
1.80 (0.071)
0.10 (0.004)
0.00 (0.00)
0.25 (0.010)
0.15 (0.006) 1.00 (0.039)
0.80 (0.031) 0.20 (0.008)
0.10 (0.004)
0.30 (0.012)
0.10 (0.004)
0.30 REF.
10°
0.425 (0.017)
TYP.
DIMENSIONS ARE IN MILLIMETERS (INCHES)
PACKAGE
MARKING
CODE (XX)
X X X
DATE CODE (X)
88759/02-5.PM6.0J 2001.04.25, 6:42 PMPage 11 AdobePageMaker6.0J/PPC
12
www.semiconductor.agilent.com
Data subject to change.
Copyright © 2000 Agilent Technologies
Obsoletes 5968-2356E, 5968-5934E
5968-8014E (1/00)
Tape Dimensions and Product Orientation
For Outline SOT-323 (SC-70 3 Lead)
P
P
0
P
2
FW
C
D
1
D
E
A
0
8° MAX.
t
1
(CARRIER TAPE THICKNESS) T
t
(COVER TAPE THICKNESS)
5° MAX.
B
0
K
0
DESCRIPTION SYMBOL SIZE (mm) SIZE (INCHES)
LENGTH
WIDTH
DEPTH
PITCH
BOTTOM HOLE DIAMETER
A
0
B
0
K
0
P
D
1
2.24 ± 0.10
2.34 ± 0.10
1.22 ± 0.10
4.00 ± 0.10
1.00 + 0.25
0.088 ± 0.004
0.092 ± 0.004
0.048 ± 0.004
0.157 ± 0.004
0.039 + 0.010
CAVITY
DIAMETER
PITCH
POSITION
D
P
0
E
1.55 ± 0.05
4.00 ± 0.10
1.75 ± 0.10
0.061 ± 0.002
0.157 ± 0.004
0.069 ± 0.004
PERFORATION
WIDTH
THICKNESS W
t
1
8.00 ± 0.30
0.255 ± 0.013 0.315 ± 0.012
0.010 ± 0.0005
CARRIER TAPE
CAVITY TO PERFORATION
(WIDTH DIRECTION)
CAVITY TO PERFORATION
(LENGTH DIRECTION)
F
P
2
3.50 ± 0.05
2.00 ± 0.05
0.138 ± 0.002
0.079 ± 0.002
DISTANCE
WIDTH
TAPE THICKNESS C
T
t
5.4 ± 0.10
0.062 ± 0.001 0.205 ± 0.004
0.0025 ± 0.00004
COVER TAPE
Device Orientation
USER
FEED
DIRECTION COVER TAPE
CARRIER
TAPE
REEL END VIEW
8 mm
4 mm
TOP VIEW
### ### ### ###
Note: “###” represents Package Marking Code.
Package marking is right side up with carrier tape
perforations at top. Conforms to Electronic
Industries RS-481, “Taping of Surface Mounted
Components for Automated Placement.”
Standard quantity is 3,000 devices per reel.
88759/02-5.PM6.0J 2001.04.25, 6:42 PMPage 12 AdobePageMaker6.0J/PPC
13
t
CW
F
E
EMBOSSMENT
P
2
10 PITCHES CUMULATIVE
TOLERANCE ON TAPE
±0.2 MM (±0.008)
USER FEED
DIRECTION
P
0
D
0
COVER
TAPE
T
P
1
D
1
K
DESCRIPTION SYMBOL SIZE (mm) SIZE (INCHES)
LENGTH
WIDTH
DEPTH
PITCH
BOTTOM HOLE DIAMETER
A
B
K
P
1
D
1
3.15 ± 0.15
2.65 ± 0.25
1.30 ± 0.10
4.00 ± 0.10
1.00 min.
0.124 ± 0.006
0.104 ± 0.010
0.051 ± 0.004
0.157 ± 0.004
0.04 min.
CAVITY
DIAMETER
PITCH
POSITION
D
0
P
0
E
1.55 + 0.10/-0
4.00 ± 0.10
1.75 ± 0.10
0.061 + 0.004/-0
0.157 ± 0.004
0.069 ± 0.004
PERFORATION
WIDTH
THICKNESS W
t8.00 ± 0.2
0.30 ± 0.05 0.315 ± 0.008
0.012 ± 0.002
CARRIER TAPE
CAVITY TO PERFORATION
(WIDTH DIRECTION)
CAVITY TO PERFORATION
(LENGTH DIRECTION)
F
P
2
3.50 ± 0.10
2.00 ± 0.05
0.138 ± 0.004
0.079 ± 0.002
DISTANCE
BETWEEN
CENTERLINE
WIDTH
TAPE THICKNESS C
T5.40 ± 0.25
0.064 ± 0.01 0.205 ± 0.010
0.003 ± 0.0004
COVER TAPE
B
CENTER LINES
OF CAVITY
A
Tape Dimensions and Product Orientation
For Outline SOT-23
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14
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仕様及び仕様書に関して
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です。ご使用において第三者の知的財産権などの保証または実施権の許諾に対して問題が発生し
た場合、当社はその責任を負いかねます。
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