HSMS-2700-BLKG - Agilent / Hewlett-Packard

High Performance Schottky

Diode for Transient Suppression

Technical Data

Features

• Ultra-low Series Resistance

for Higher Current Handling

• Picosecond Switching

• Low Capacitance

• Lead-free Option Available

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 capacitance mini-

mizes waveshape loss that causes

signal degradation.

HSMS-2700/-2702

-270B/-270C

SERIES

2, C

SINGLE

0, B

HSMS-270x DC Electrical Specifications, TA = +25°C[1]

Maximum Minimum Typical Maximum

Part Package Forward Breakdown Typical Series Eff. Carrier

Number Marking Lead Voltage Voltage Capacitance Resistance Lifetime

HSMS- Code

[2]

Code Configuration Package V

(mV) V

(V) C

(pF) R

(Ω)τ (ps)

-2700

Single

SOT-23

-270B B SOT-323

(3-lead SC-70)

-2702 2 SOT-23

-270C

Series SOT-323

(3-lead SC-70)

550[3] 15[4] 6.7[5] 0.65 100[6]

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. IF = 100 µA; 100% tested

5. VF = 0; f =1 MHz

6. Measured with Karkauer method at 20 mA; guaranteed by design.

Absolute Maximum Ratings, TA= 25ºC

Symbol Parameter Unit Absolute Maximum[1]

HSMS-2700/-2702 HSMS-270B/-270C

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.

0.08 pF

SPICE model

2 nH

Linear and Non-linear SPICE Model SPICE Parameters

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

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

100

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.

0 5 10 20

CT – TOTAL CAPACITANCE (pF)

VF – REVERSE VOLTAGE (V)

TA = +75°C

TA = +25°C

TA = –25°C

0 50 150100 300

250

200 350

TJ – JUNCTION TEMPERATURE (°C)

IF – FORWARD CURRENT (mA)

140

120

100

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)

140

120

100

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

100

0.1

500

TA = +75°C

TA = +25°C

TA = –25°C

Package Dimensions

Outline SOT-23

Tape Dimensions and Product Orientation

For Outline SOT-23

SIDE VIEW

TOP VIEW

END VIEW

DIMENSIONS ARE IN MILLIMETERS

(

INCHES

)

1.02 (0.040)

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)

1.02 (0.041)

0.85 (0.033)

0.152 (0.006)

0.066 (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)

X X X

PACKAGE

MARKING

CODE (XX)

DATE CODE (X)

Device Orientation

For Outlines SOT-23/323

Note: "AB" represents package marking code.

"C" represents date code.

END VIE

8 mm

4 mm

TOP VIEW

ABC ABC ABC ABC

USER

FEED

DIRECTION

COVER TAPE

CARRIER

TAPE

REEL

9° MAX

Ko 8° MAX

13.5° MAX

DESCRIPTION SYMBOL SIZE (mm) SIZE (INCHES)

LENGTH

WIDTH

DEPTH

PITCH

BOTTOM HOLE DIAMETER

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

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

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)

3.50 ± 0.05

2.00 ± 0.05

0.138 ± 0.002

0.079 ± 0.002

DISTANCE

BETWEEN

CENTERLINE

Package Dimensions

Outline SOT-323 (SC-70 3 Lead)

Tape Dimensions and Product Orientation

For 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)

8° MAX.

(CARRIER TAPE THICKNESS) T

(COVER TAPE THICKNESS)

8° MAX.

DESCRIPTION SYMBOL SIZE (mm) SIZE (INCHES)

LENGTH

WIDTH

DEPTH

PITCH

BOTTOM HOLE DIAMETER

2.40 ± 0.10

1.20 ± 0.10

4.00 ± 0.10

1.00 + 0.25

0.094 ± 0.004

0.047 ± 0.004

0.157 ± 0.004

0.039 + 0.010

CAVITY

DIAMETER

PITCH

POSITION

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

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)

3.50 ± 0.05

2.00 ± 0.05

0.138 ± 0.002

0.079 ± 0.002

DISTANCE

WIDTH

TAPE THICKNESS

5.4 ± 0.10

0.062 ± 0.001

0.205 ± 0.004

0.0025 ± 0.00004

COVER TAPE

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 differ-

ence 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 involv-

ing 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 poten-

tial 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 frequencies 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.

CURRENT

0.6V

+–

BIAS VOLTAGE

PN JUNCTION

CAPACITANCE

METAL

CURRENT

0.3V

+–

BIAS VOLTAGE

SCHOTTKY JUNCTION

CAPACITANCE

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 applica-

tions. 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 satura-

tion 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.

HSMS- HBAT-

Parameter 270x 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 Ω2.4 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 capability.

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.

IF – FORWARD CURRENT (mA)

VF – FORWARD VOLTAGE (V)

.01

300

100

0 0.1 0.30.2 0.50.4 0.6

HSMS-270x

HBAT-540x

Figure 7. Forward Current vs.

Forward Voltage at 25°C.

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/clamp-

ing diode is to handle high cur-

rents, 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.

current

limiting

pull-down

(or pull-up)

long cross-site cable

noisy data-spikes

voltage limited to

Vs + Vd

0V – Vd

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.

0 0.1 0.2 0.3 0.50.4

VF – FORWARD VOLTAGE (V)

IF – FORWARD CURRENT (mA)

Rs = 7.7 Ω

Rs = 1.0 Ω

Figure 9. Comparison of Two

Diodes.

The first is a conventional

Schottky diode of the type gener-

ally 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 termi-

nals 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 maintained 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 simulta-

neously solved.

IF = IS e –1

11600 (V F – IFRS)

nTJ(1)

IS = I0 e

298

–4060 –(2)

TJ = VFIFθJC + TA (3)

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 for-

ward V-I curve of a Schottky

diode. Equation (2) provides the

value for the diode’s saturation

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 resistance 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 Agilent. 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

Part Number Ordering Information

Part Number No. of Devices Container

HSMS-2700-BLK 100 Antistatic Bag

HSMS-2700-TR1 3,000 7" Reel

HSMS-2700-TR2 10,000 13" Reel

HSMS-2702-BLK 100 Antistatic Bag

HSMS-2702-TR1 3,000 7" Reel

HSMS-2702-TR2 10,000 13" Reel

HSMS-270B-BLK 100 Antistatic Bag

HSMS-270B-TR1 3,000 7" Reel

HSMS-270B-TR2 10,000 13" Reel

HSMS-270C-BLK 100 Antistatic Bag

HSMS-270C-TR1 3,000 7" Reel

HSMS-270C-TR2 10,000 13" Reel

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 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 capabil-

ity of any Agilent diode.

www.agilent.com/semiconductors

For product information and a complete list of

distributors, please go to our web site.

For technical assistance call:

Americas/Canada: +1 (800) 235-0312 or

(916) 788-6763

Europe: +49 (0) 6441 92460

China: 10800 650 0017

Hong Kong: (65) 6756 2394

India, Australia, New Zealand: (65) 6755 1939

Japan: (+81 3) 3335-8152(Domestic/International), or

0120-61-1280(Domestic Only)

Korea: (65) 6755 1989

Singapore, Malaysia, Vietnam, Thailand, Philippines,

Indonesia: (65) 6755 2044

Taiwan: (65) 6755 1843

Data subject to change.

Obsoletes 5968-2351E

March 24, 2004

5989-0473EN

Note: For lead-free option, the part number will have the character "G"

at the end, eg. HSMS-270x-TR2G for a 10,000 lead-free reel.