BAW56WT1-D - ON Semiconductor

Dual Switching Diode

MAXIMUM RATINGS (TA = 25°C)

Rating Symbol Max Unit

Reverse Voltage VR70 Vdc

Forward Current IF200 mAdc

Peak Forward Surge Current IFM(surge) 500 mAdc

THERMAL CHARACTERISTICS

Characteristic Symbol Max Unit

Total Device Dissipation FR–5 Board(1)

TA = 25°C

Derate above 25°C

PD200

1.6

mW/°C

Thermal Resistance, Junction to Ambient RJA 0.625 °C/W

Total Device Dissipation

Alumina Substrate(2) TA = 25°C

Derate above 25°C

PD300

2.4

mW/°C

Thermal Resistance, Junction to Ambient RJA 417 °C/W

Junction and Storage Temperature TJ, Tstg –55 to +150 °C

DEVICE MARKING

BAW56WT1 = A1

ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted)

Characteristic Symbol Min Max Unit

OFF CHARACTERISTICS

Reverse Breakdown Voltage

(I(BR) = 100 µAdc) V(BR) 70 — Vdc

Reverse Voltage Leakage Current

(VR = 25 Vdc, TJ = 150°C)

(VR = 70 Vdc)

(VR = 70 Vdc, TJ = 150°C)

IR—

—

2.5

µAdc

Diode Capacitance

(VR = 0, f = 1.0 MHz) CD— 2.0 pF

Forward Voltage

(IF = 1.0 mAdc)

(IF = 10 mAdc)

(IF = 60 mAdc)

(IF = 150 mAdc)

VF—

—

715

855

1000

1250

mVdc

Reverse Recovery Time

(IF = IR = 10 mAdc, RL = 100 Ω, IR(REC) = 1.0 mAdc) (Figure 1) trr — 6.0 ns

1. FR–5 = 1.0  0.75  0.062 in.

2. Alumina = 0.4  0.3  0.024 in. 99.5% alumina.

Preferred devices are ON Semiconductor recommended choices for future use and best overall value.

ON Semiconductor

 Semiconductor Components Industries, LLC, 2001

March, 2001 – Rev. 1 1Publication Order Number:

BAW56WT1/D

BAW56WT1

ON Semiconductor Preferred Device

CASE 419–04, STYLE 4

SC–70/SOT–323

ANODE

CATHODE

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Notes: 1. A 2.0 kΩ variable resistor adjusted for a Forward Current (IF) of 10 mA.

Notes: 2. Input pulse is adjusted so IR(peak) is equal to 10 mA.

Notes: 3. tp » trr

+10 V 2.0 k

820 Ω

0.1 µF

DUT

100 µH

0.1 µF

50 Ω OUTPUT

PULSE

GENERATOR

50 Ω INPUT

SAMPLING

OSCILLOSCOPE

trtpt

10%

90%

trr t

iR(REC) = 1.0 mA

OUTPUT PULSE

(IF = IR = 10 mA; MEASURED

at iR(REC) = 1.0 mA)

INPUT SIGNAL

Figure 1. Recovery Time Equivalent Test Circuit

100

0.2 0.4

VF, FORWARD VOLTAGE (VOLTS)

0.6 0.8 1.0 1.2

1.0

0.1

TA = 85°C

VR, REVERSE VOLTAGE (VOLTS)

1.0

0.1

0.01

0.001

10 20 30 40 50

1.75

VR, REVERSE VOLTAGE (VOLTS)

1.5

1.25

1.0

0.75

CD, DIODE CAPACITANCE (pF)

246 8

IF, FORWARD CURRENT (mA)

Figure 2. Forward Voltage Figure 3. Leakage Current

Figure 4. Capacitance

TA = -40°C

TA = 25°C

TA = 150°C

TA = 125°C

TA = 85°C

TA = 55°C

TA = 25°C

IR, REVERSE CURRENT (µA)

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MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS

Surface mount board layout is a critical portion of the total

design. The footprint for the semiconductor packages must

be the correct size to insure proper solder connection

interface between the board and the package. With the

correct pad geometry, the packages will self align when

subjected to a solder reflow process.

inches

0.035

0.9

0.075

0.7

1.9

0.028

0.65

0.025

0.65

0.025

SC-70/SOT-323 POWER DISSIPATION

The power dissipation of the SC-70/SOT-323 is a function

of the collector pad size. This can vary from the minimum

pad size for soldering to the pad size given for maximum

power dissipation. Power dissipation for a surface mount

device is determined by TJ(max), the maximum rated

junction temperature of the die, RθJA, the thermal resistance

from the device junction to ambient; and the operating

temperature, TA. Using the values provided on the data

sheet, PD can be calculated as

follows.

PD = TJ(max) – TA

RθJA

The values for the equation are found in the maximum

ratings table on the data sheet. Substituting these values into

the equation for an ambient temperature TA of 25°C, one can

calculate the power dissipation of the device which in this

case is 200

milliwatts.

PD = 150°C – 25°C

0.625°C/W = 200 milliwatts

The 0.625°C/W assumes the use of the recommended

footprint on a glass epoxy printed circuit board to achieve a

power dissipation of 200 milliwatts. Another alternative

would be to use a ceramic substrate or an aluminum core

board such as Thermal Clad. Using a board material such

as Thermal Clad, a power dissipation of 300 milliwatts can

be achieved using the same footprint.

SOLDERING PRECAUTIONS

The melting temperature of solder is higher than the rated

temperature of the device. When the entire device is heated

to a high temperature, failure to complete soldering within

a short time could result in device failure. Therefore, the

following items should always be observed in order to

minimize the thermal stress to which the devices are

subjected.

•Always preheat the device.

•The delta temperature between the preheat and

soldering should be 100°C or less.*

•When preheating and soldering, the temperature of the

leads and the case must not exceed the maximum

temperature ratings as shown on the data sheet. When

using infrared heating with the reflow soldering

method, the difference should be a maximum of 10°C.

•The soldering temperature and time should not exceed

260°C for more than 10 seconds.

•When shifting from preheating to soldering, the

maximum temperature gradient should be 5°C or less.

•After soldering has been completed, the device should

be allowed to cool naturally for at least three minutes.

Gradual cooling should be used as the use of forced

cooling will increase the temperature gradient and

result in latent failure due to mechanical stress.

•Mechanical stress or shock should not be applied

during cooling

* Soldering a device without preheating can cause

excessive thermal shock and stress which can result in

damage to the device.

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SOLDER STENCIL GUIDELINES

Prior to placing surface mount components onto a printed

circuit board, solder paste must be applied to the pads. A

solder stencil is required to screen the optimum amount of

solder paste onto the footprint. The stencil is made of brass

or stainless steel with a typical thickness of 0.008 inches.

The stencil opening size for the surface mounted package

should be the same as the pad size on the printed circuit

board, i.e., a 1:1 registration.

TYPICAL SOLDER HEATING PROFILE

For any given circuit board, there will be a group of

control settings that will give the desired heat pattern. The

operator must set temperatures for several heating zones,

and a figure for belt speed. Taken together, these control

settings make up a heating “profile” for that particular

circuit board. On machines controlled by a computer, the

computer remembers these profiles from one operating

session to the next. Figure 5 shows a typical heating profile

for use when soldering a surface mount device to a printed

circuit board. This profile will vary among soldering

systems b u t i t i s a good starting point. Factors that can a ffect

the profile include the type of soldering system in use,

density and types of components on the board, type of solder

used, and the type of board or substrate material being used.

This profile shows temperature versus time. The line on the

graph shows the actual temperature that might be

experienced o n the surface of a test board at or near a central

solder joint. The two profiles are based on a high density an d

a low density board. The Vitronics SMD310

convection/infrared reflow soldering system was used to

generate this profile. The type of solder used was 62/36/2

Tin Lead Silver with a melting point between 177–189°C.

When this type of furnace is used for solder reflow work, the

circuit boards and solder joints tend to heat first. The

components o n the board are then heated by conduction. The

circuit board, because it has a lar ge surface area, absorbs the

thermal ener gy more ef ficiently, then distributes this ener gy

to the components. Because of this effect, the main body of

a component may be up to 30 degrees cooler than the

adjacent solder joints.

STEP 1

PREHEAT

ZONE 1

RAMP"

STEP 2

VENT

SOAK"

STEP 3

HEATING

ZONES 2 & 5

RAMP"

STEP 4

HEATING

ZONES 3 & 6

SOAK"

STEP 5

HEATING

ZONES 4 & 7

SPIKE"

STEP 6

VENT

STEP 7

COOLING

200°C

150°C

100°C

50°C

TIME (3 TO 7 MINUTES TOTAL) TMAX

SOLDER IS LIQUID FOR

40 TO 80 SECONDS

(DEPENDING ON

MASS OF ASSEMBLY)

205° TO 219°C

PEAK AT

SOLDER JOINT

DESIRED CURVE FOR LOW

MASS ASSEMBLIES

100°C

150°C

160°C

140°C

Figure 5. Typical Solder Heating Profile

DESIRED CURVE FOR HIGH

MASS ASSEMBLIES

170°C

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PACKAGE DIMENSIONS

CASE 419–04

ISSUE L

SC–70 (SOT–323)

NOTES:

1. DIMENSIONING AND TOLERANCING PER ANSI

Y14.5M, 1982.

2. CONTROLLING DIMENSION: INCH.

DIM MIN MAX MIN MAX

MILLIMETERSINCHES

A0.071 0.087 1.80 2.20

B0.045 0.053 1.15 1.35

C0.032 0.040 0.80 1.00

D0.012 0.016 0.30 0.40

G0.047 0.055 1.20 1.40

H0.000 0.004 0.00 0.10

J0.004 0.010 0.10 0.25

K0.017 REF 0.425 REF

L0.026 BSC 0.650 BSC

N0.028 REF 0.700 REF

S0.079 0.095 2.00 2.40

0.05 (0.002)

STYLE 4:

PIN 1. CATHODE

2. CATHODE

3. ANODE

BAW56WT1

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Notes

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Notes

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without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular

purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability,

including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or

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For additional information, please contact your local

Sales Representative.

BAW56WT1/D

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