HSMS-2700, 2702, 270B, 270C, 270P
High Performance Schottky Diode
for Transient Suppression
Data Sheet
Features
• Ultra-low Series Resistance for Higher Current
Handling
• Picosecond Switching
• Low Capacitance
• Lead-free
Applications
RF and computer designs that require circuit protection,
high-speed switching, and voltage clamping.
Package Lead Code Identification (Top View)
Description
The HSMS-2700 series of Schottky diodes, commonly
referred to as clipping/clamping diodes, are optimal for
circuit and waveshape preservation applications with
high speed switching. Ultra-low series resistance, RS,
makes them ideal for protecting sensitive circuit elements
against higher current transients carried on data lines.
With picosecond switching, the HSMS-270x can respond
to noise spikes with rise times as fast as 1 ns. Low ca-
pacitance minimizes waveshape loss that causes signal
degradation.
HSMS-270x DC Electrical Specifications, TA = +25°C[1]
Part
Number
HSMS-
Package
Marking
Code[2]
Lead
Code Configuration Package
Maximum
Forward
Voltage
VF (mV)
Minimum
Breakdown
Voltage
VBR (V)
Typical
Capacitance
CT (pF)
Typical
Series
Resistance
RS (Ω)
Maximum
Eff. Carrier
Lifetime
τ (ps)
-2700 J0 0 Single SOT-23
550[3] 15[4] 6.7[5] 0.65 100[6]
-270B B SOT-323
(3-lead SC-70)
-2702 2 SOT-23
-270C J2 C Series SOT-323
(3-lead SC-70)
-270P JP P Bridge Quad SOT-363
(6-lead SC-70)
Notes:
1. TA = +25°C, where TA is defined to be the temperature at the package pins where contact is made to the circuit board.
2. Package marking code is laser marked.
3. IF = 100 mA; 100% tested
4. IR = 100 μA; 100% tested
5. VF = 0; f =1 MHz
6. Measured with Karkauer method at 20 mA; guaranteed by design.
SERIES
2, C
SINGLE
0, B
1212123
65433
BRIDGE QUAD
2
Absolute Maximum Ratings, TA= 25ºC
Symbol Parameter Unit
Absolute Maximum[1]
HSMS-2700/-2702 HSMS-270B/270C/270P
IFDC Forward Current mA 350 750
IF-peak Peak Surge Current (1μs pulse) A 1.0 1.0
PTTotal Power Dissipation mW 250 825
PINV Peak Inverse Voltage V 15 15
TJJunction Temperature °C 150 150
TSTG Storage Temperature °C -65 to 150 -65 to 150
θJC Thermal Resistance, junction to lead °C/W 500 150
Note:
1. Operation in excess of any one of these conditions may result in permanent damage to the device.
Linear and Non-linear SPICE Model
Parameter Unit Value
BV V 25
CJO pF 6.7
EG eV 0.55
IBV A 10E-4
IS A 1.4E-7
N 1.04
RS Ω0.65
PB V 0.6
PT 2
M 0.5
SPICE Parameters
R
S
0.08 pF
SPICE model
2 nH
3
Typical Performance
Figure 2. Forward Current vs. Forward Voltage at
Temperature for HSMS-270B and HSMS-270C.
0 0.1 0.30.2 0.50.4 0.6
IF – FORWARD CURRENT (mA)
VF – FORWARD VOLTAGE (V)
Figure 1. Forward Current vs. Forward Voltage at
Temperature for HSMS-2700 and HSMS-2702.
0.01
10
100
1
0.1
300
TA = +75 C
TA = +25 C
TA = –25 C
Figure 3. Junction Temperature vs. Forward Current
as a Function of Heat Sink Temperature for the
HSMS-2700 and HSMS-2702.
Note: Data is calculated from SPICE parameters.
Figure 5. Total Capacitance vs. Reverse Voltage.
0510 20
CT – TOTAL CAPACITANCE (pF)
VF – REVERSE VOLTAGE (V)
15
1
3
2
7
4
6
5
TA = +75 C
TA = +25 C
TA = –25 C
050 150100 300
250
200 350
TJ – JUNCTION TEMPERATURE ( C)
IF – FORWARD CURRENT (mA)
0
140
120
100
80
60
40
20
160
Max. safe junction temp.
Figure 4. Junction Temperature vs. Current as a
Function of Heat Sink Temperature for HSMS-270B
and HSMS-270C.
Note: Data is calculated from SPICE parameters.
TA = +75 C
TA = +25 C
TA = –25 C
0 150 450300 600 750
TJ – JUNCTION TEMPERATURE ( C)
IF – FORWARD CURRENT (mA)
0
140
120
100
80
60
40
20
160
Max. safe junction temp.
0 0.1 0.30.2 0.50.4 0.80.70.6
IF – FORWARD CURRENT (mA)
VF – FORWARD VOLTAGE (V)
0.01
10
100
1
0.1
500
TA = +75 C
TA = +25 C
TA = –25 C
4
Package Dimensions
Outline SOT-23
Tape Dimensions and Product Orientation
For Outline SOT-23
Device Orientation
For Outlines SOT-23/323
0.039
1
0.039
1
0.079
2.0
0.031
0.8
Dimensions in inches
mm
0.035
0.9
9° MAX
A
0
P
P
0
D
P
2
E
F
W
D
1
Ko 8° MAX
B
0
13.5° MAX
t1
DESCRIPTION SYMBOL SIZE (mm) SIZE (INCHES)
LENGTH
WIDTH
DEPTH
PITCH
BOTTOM HOLE DIAMETER
A
0
B
0
K
0
P
D
1
3.15 ± 0.10
2.77 ± 0.10
1.22 ± 0.10
4.00 ± 0.10
1.00 + 0.05
0.124 ± 0.004
0.109 ± 0.004
0.048 ± 0.004
0.157 ± 0.004
0.039 ± 0.002
CAVITY
DIAMETER
PITCH
POSITION
D
P
0
E
1.50 + 0.10
4.00 ± 0.10
1.75 ± 0.10
0.059 + 0.004
0.157 ± 0.004
0.069 ± 0.004
PERFORATION
WIDTH
THICKNESS
W
t1
8.00 + 0.30 – 0.10
0.229 ± 0.013
0.315 + 0.012 – 0.004
0.009 ± 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
BETWEEN
CENTERLINE
Recommended PCB Pad Layout
For Avago’s SOT-23 Products
Note: "AB" represents package marking code.
"C" represents date code.
END VIEW
8 mm
4 mm
TOP VIEW
ABC ABC ABC ABC
USER
FEED
DIRECTION
COVER TAPE
CARRIER
TAPE
REEL
e
B
e2
e1
E1
C
EXXX
L
D
A
A1
Notes:
XXX-package marking
Drawings are not to scale
DIMENSIONS (mm)
MIN.
0.79
0.000
0.30
0.08
2.73
1.15
0.89
1.78
0.45
2.10
0.45
MAX.
1.20
0.100
0.54
0.20
3.13
1.50
1.02
2.04
0.60
2.70
0.69
SYMBOL
A
A1
B
C
D
E1
e
e1
e2
E
L
5
Package Dimensions
Outline SOT-323 (SC-70 3 Lead)
0.026
0.039
0.079
0.022
Dimensions in inches
Recommended PCB Pad Layout
For Avago’s SC70 3L/SOT-323 Products
e
B
e1
E1
C
EXXX
L
D
A
A1
Notes:
XXX-package marking
Drawings are not to scale
DIMENSIONS (mm)
MIN.
0.80
0.00
0.15
0.08
1.80
1.10
1.80
0.26
MAX.
1.00
0.10
0.40
0.25
2.25
1.40
2.40
0.46
SYMBOL
A
A1
B
C
D
E1
e
e1
E
L
1.30 typical
0.65 typical
Outline SOT-363 (SC-70 6 Lead)
E
HE
D
e
A1
b
A
A2
L
c
DIMENSIONS (mm)
MIN.
1.15
1.80
1.80
0.80
0.80
0.00
0.15
0.08
0.10
MAX.
1.35
2.25
2.40
1.10
1.00
0.10
0.30
0.25
0.46
SYMBOL
E
D
HE
A
A2
A1
e
b
c
L
0.650 BCS
6
Tape Dimensions and Product Orientation
For Outline SOT-323/363 (SC-70 3 and 6 Lead)
P
P
0
P
2
F
W
C
D
1
D
E
A
0
8° MAX.
t
1
(CARRIER TAPE THICKNESS) T
t
(COVER TAPE THICKNESS)
8° 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
2.40 ± 0.10
2.40 ± 0.10
1.20 ± 0.10
4.00 ± 0.10
1.00 + 0.25
0.094 ± 0.004
0.094 ± 0.004
0.047 ± 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
0.254 ± 0.02
0.315 ± 0.012
0.0100 ± 0.0008
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
7
Applications Information
Schottky Diode Fundamentals
The HSMS-270x series of clipping/clamping diodes
are Schottky devices. A Schottky device is a rectifying,
metal-semiconductor contact formed between a metal
and an n-doped or a p-doped semiconductor. When a
metal-semiconductor junction is formed, free electrons
flow across the junction from the semiconductor and fill
the free-energy states in the metal. This flow of electrons
creates a depletion or potential across the junction. The
difference in energy levels between semiconductor and
metal is called a Schottky barrier.
P-doped, Schottky-barrier diodes excel at applications
requiring ultra low turn-on voltage (such as zero-biased
RF detectors). But their very low, breakdown-voltage
and high series-resistance make them unsuitable for
the clipping and clamping applications involving high
forward currents and high reverse voltages. Therefore,
this discussion will focus entirely on n-doped Schottky
diodes.
Under a forward bias (metal connected to positive in an
n-doped Schottky), or forward voltage, VF, there are many
electrons with enough thermal energy to cross the barrier
potential into the metal. Once the applied bias exceeds
the built-in potential of the junction, the forward current,
IF, will increase rapidly as VF increases.
When the Schottky diode is reverse biased, the potential
barrier for electrons becomes large; hence, there is a
small probability that an electron will have sufficient
thermal energy to cross the junction. The reverse leakage
current will be in the nanoampere to microampere range,
depending upon the diode type, the reverse voltage, and
the temperature.
In contrast to a conventional p-n junction, current in
the Schottky diode is carried only by majority carriers
(electrons). Because no minority-carrier (hole) charge
storage effects are present, Schottky diodes have carrier
lifetimes of less than 100 ps. This extremely fast switching
time makes the Schottky diode an ideal rectifier at fre-
quencies of 50 GHz and higher.
Another significant difference between Schottky and p-n
diodes is the forward voltage drop. Schottky diodes have
a threshold of typically 0.3 V in comparison to that of 0.6 V
in p-n junction diodes. See Figure 6.
Through the careful manipulation of the diameter of the
Schottky contact and the choice of metal deposited on
the n-doped silicon, the important characteristics of the
diode (junction capacitance, CJ; parasitic series resistance,
RS; breakdown voltage, VBR; and forward voltage, VF,)
can be optimized for specific applications. The HSMS-
270x series and HBAT-540x series of diodes are a case in
point.
Both diodes have similar barrier heights; and this is
indicated by corresponding values of saturation current,
IS. Yet, different contact diameters and epitaxial-layer
thickness result in very different values of CJ and RS. This
is seen by comparing their SPICE parameters in Table 1.
Table 1. HSMS-270x and HBAT-540x SPICE Parameters.
Parameter HSMS- 270x HBAT- 540x
BV 25 V 40 V
CJ0 6.7 pF 3.0 pF
EG 0.55 eV 0.55 eV
IBV 10E-4 A 10E-4 A
IS 1.4E-7 A 1.0E-7 A
N 1.04 1.0
RS 0.65 Ω 2.4 Ω
PB 0.6 V 0.6 V
PT 2 2
M 0.5 0.5
At low values of IF ≤ 1 mA, the forward voltages of the
two diodes are nearly identical. However, as current rises
above 10 mA, the lower series resistance of the HSMS-
270x allows for a much lower forward voltage. This gives
the HSMS-270x a much higher current handling capabil-
ity. The trade-off is a higher value of junction capacitance.
The forward voltage and current plots illustrate the
differences in these two Schottky diodes, as shown in
Figure 7.
PN
CURRENT
0.6V
+–
BIAS VOLTAGE
PN JUNCTION
CAPACITANCE
METAL
N
CURRENT
0.3V
+–
BIAS VOLTAGE
SCHOTTKY JUNCTION
CAPACITANCE
I
F
– FORWARD CURRENT (mA)
V
F
– FORWARD VOLTAGE (V)
.01
10
1
.1
300
100
0 0.1 0.30.2 0.50.4 0.6
HSMS-270x
HBAT-540x
Figure 6.
Figure 7. Forward Current vs. Forward Voltage at 25°C.
8
Because the automatic, pick-and-place equipment used
to assemble these products selects dice from adjacent
sites on the wafer, the two diodes which go into the
HSMS-2702 or HSMS-270C (series pair) are closely
matched—without the added expense of testing and
binning.
Current Handling in Clipping/Clamping Circuits
The purpose of a clipping/clamping diode is to handle
high currents, protecting delicate circuits downstream
of the diode. Current handling capacity is determined
by two sets of characteristics, those of the chip or device
itself and those of the package into which it is mounted.
tained at a low limit even at high values of current.
Maximum reliability is obtained in a Schottky diode when
the steady state junction temperature is maintained at or
below 150°C, although brief excursions to higher junction
temperatures can be tolerated with no significant impact
upon mean-time-to-failure, MTTF. In order to compute
the junction temperature, Equations (1) and (3) below
must be simultaneously solved.
0 0.1 0.2 0.3 0.50.4
V
F
– FORWARD VOLTAGE (V)
I
F
– FORWARD CURRENT (mA)
0
3
2
1
6
4
5
R
s
= 7.7
R
s
= 1.0
IF = IS e –1
11600 (VF – I
F
RS)
nTJ
(1)
IS = I0
e
TJ
298
2
n1
T
J
1
298
–4060 –(2)
TJ = VFIFJC
+ TA
(3)
Figure 8. Two Schottky Diodes Are Used for Clipping/Clamping in a Circuit.
Consider the circuit shown in Figure 8, in which two
Schottky diodes are used to protect a circuit from noise
spikes on a stream of digital data. The ability of the diodes
to limit the voltage spikes is related to their ability to sink
the associated current spikes. The importance of current
handling capacity is shown in Figure 9, where the forward
voltage generated by a forward current is compared in
two diodes.
Figure 9. Comparison of Two Diodes.
The first is a conventional Schottky diode of the type
generally used in RF circuits, with an RS of 7.7 Ω. The
second is a Schottky diode of identical characteristics,
save the RS of 1.0 Ω. For the conventional diode, the
relatively high value of RS causes the voltage across the
diode’s terminals to rise as current increases. The power
dissipated in the diode heats the junction, causing RS to
climb, giving rise to a runaway thermal condition. In the
second diode with low RS, such heating does not take
place and the voltage across the diode terminals is main-
where:
IF = forward current
IS = saturation current
VF = forward voltage
RS = series resistance
TJ = junction temperature
IO = saturation current at 25°C
n = diode ideality factor
θJC = thermal resistance from junction to case (diode
lead)
= θpackage + θchip
TA = ambient (diode lead) temperature
Equation (1) describes the forward V-I curve of a Schottky
diode. Equation (2) provides the value for the diode’s satu-
ration current, which value is plugged into (1). Equation
(3) gives the value of junction temperature as a function
of power dissipated in the diode and ambient (lead)
temperature.
The key factors in these equations are: RS, the series resis-
tance of the diode where heat is generated under high
current conditions; θchip, the chip thermal resistance of
the Schottky die; and θpackage, or the package thermal
resistance.
RS for the HSMS-270x family of diodes is typically 0.7 Ω
and is the lowest of any Schottky diode available from
Avago. Chip thermal resistance is typically 40°C/W; the
thermal resistance of the iron-alloy-leadframe, SOT-23
package is typically 460°C/W; and the thermal resistance
of the copper-leadframe, SOT-323 package is typically
110°C/W. The impact of package thermal resistance on
the current handling capability of these diodes can be
seen in Figures 3 and 4. Here the computed values of
junction temperature vs. forward current are shown
current
limiting
pull-down
(or pull-up)
long cross-site cable
noisy data-spikes
Vs
0V
voltage limited to
Vs + Vd
0V – Vd
Part Number Ordering Information
Part Number No. of Devices Container
HSMS-2700-BLKG
HSMS-2700-TR1G
HSMS-2700-TR2G
100
3,000
10,000
Antistatic Bag
7" Reel
13" Reel
HSMS-2702-BLKG
HSMS-2702-TR1G
HSMS-2702-TR2G
100
3,000
10,000
Antistatic Bag
7" Reel
13" Reel
HSMS-270B-BLKG
HSMS-270B-TR1G
HSMS-270B-TR2G
100
3,000
10,000
Antistatic Bag
7" Reel
13" Reel
HSMS-270C-BLKG
HSMS-270C-TR1G
HSMS-270C-TR2G
100
3,000
10,000
Antistatic Bag
7" Reel
13" Reel
HSMS-270P-BLKG
HSMS-270P-TR1G
100
3,000
Antistatic Bag
7" Reel
For product information and a complete list of distributors, please go to our web site: www.avagotech.com
Avago, Avago Technologies, and the A logo are trademarks of Avago Technologies Limited in the United States and other countries.
Data subject to change. Copyright © 2005-2010 Avago Technologies Limited. All rights reserved.
Obsoletes 5989-0473EN
AV02-1366EN - July 7, 2010
for three values of ambient temperature. The SOT-323
products, with their copper leadframes, can safely handle
almost twice the current of the larger SOT-23 diodes.
Note that the term “ambient temperature” refers to the
temperature of the diode’s leads, not the air around the
circuit board. It can be seen that the HSMS-270B and
HSMS-270C products in the SOT-323 package will safely
withstand a steady-state forward current of 550 mA when
the diode’s terminals are maintained at 75°C.
For pulsed currents and transient current spikes of less
than one microsecond in duration, the junction does not
have time to reach thermal steady state. Moreover, the
diode junction may be taken to temperatures higher than
150°C for short time-periods without impacting device
MTTF. Because of these factors, higher currents can be
safely handled. The HSMS-270x family has the highest
current handling capability of any Avago diode.
